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Guillain-Barre syndrome-------------
Guillain-Barré syndrome (GBS) is a disorder in which the body's immune system attacks part of the peripheral nervous system. The first symptoms of this disorder include varying degrees of weakness or tingling sensations in the legs. In many instances the symmetrical weakness and abnormal sensations spread to the arms and upper body. These symptoms can increase in intensity until certain muscles cannot be used at all and, when severe, the person is almost totally paralyzed. In these cases the disorder is life threatening - potentially interfering with breathing and, at times, with blood pressure or heart rate - and is considered a medical emergency. Such an individual is often put on a ventilator to assist with breathing and is watched closely for problems such as an abnormal heart beat, infections, blood clots, and high or low blood pressure. Most individuals, however, have good recovery from even the most severe cases of Guillain-Barré syndrome, although some continue to have a certain degree of weakness.

Usually Guillain-Barré occurs a few days or weeks after the patient has had symptoms of a respiratory or gastrointestinal viral infection. Occasionally surgery will trigger the syndrome.

After the first clinical manifestations of the disease, the symptoms can progress over the course of hours, days, or weeks. Most people reach the stage of greatest weakness within the first 2 weeks after symptoms appear, and by the third week of the illness 90 percent of all patients are at their weakest.

When Guillain-Barré is preceded by a viral or bacterial infection, it is possible that the virus has changed the nature of cells in the nervous system so that the immune system treats them as foreign cells. It is also possible that the virus makes the immune system itself less discriminating about what cells it recognizes as its own, allowing some of the immune cells, such as certain kinds of lymphocytes and macrophages, to attack the myelin. Sensitized T lymphocytes cooperate with B lymphocytes to produce antibodies against components of the myelin sheath and may contribute to destruction of the myelin. In two forms of GBS, axons are attacked by antibodies against the bacteria ****Campylobacter jejuni, which react with proteins of the peripheral nerves


Multiple sclerosis

Multiple sclerosis:
Multiple sclerosis (MS) is a potentially disabling disease of the brain and spinal cord (central nervous system).

In MS, the immune system attacks the protective sheath (myelin) that covers nerve fibers and causes communication problems between your brain and the rest of your body. Eventually, the disease can cause the nerves themselves to deteriorate or become permanently damaged.

Signs and symptoms of MS vary widely and depend on the amount of nerve damage and which nerves are affected. Some people with severe MS may lose the ability to walk independently or at all, while others may experience long periods of remission without any new symptoms.

There's no cure for multiple sclerosis. However, treatments can help speed recovery from attacks, modify the course of the disease and manage symptoms.

This damage disrupts the ability of parts of the nervous system to communicate, resulting in a range of signs and symptoms, including physical, mental, and sometimes psychiatric problems.[5][8][9] Specific symptoms can include double vision, blindness in one eye, muscle weakness, trouble with sensation, or trouble with coordination.[1] MS takes several forms, with new symptoms either occurring in isolated attacks (relapsing forms) or building up over time (progressive forms).[10] Between attacks, symptoms may disappear completely; however, permanent neurological problems often remain, especially as the disease advances.[10]


What is Cushing's triad

Cushing’s triad: hypertension, bradycardia
and irregular respirations (brainstem)

Caused by increased intracranial pressure


Describe the clinical features and pathophysiology of Werdnig-
Hoffman disease

Most common (and severe) type of spinal muscle atrophy is SMA I Werdnig-Hoffmann disease

“acute infantile spinal muscle atrophy”
autosomal-recessive inheritance pattern “floppy-baby”
median age of death is 6-7 months. affects 1/10,000 lives births
Weakness and muscle wasting in
bulbar muscles - sucking swallowing breathing


Uncal herniation

Results in: oculomotor paresis ipsilateral, dilated pupil), contralateral hemiparesis:
 Contralateral hemiparesis occurs with compression of the ipsilateral cerebral peduncle of the midbrain -  Since the corticospinal tracts decussate below the midbrain, the hemiparesis is contrateral

 In addition to pupillary dilatation, a second key feature of uncal herniation is a decreasing level of consciousness (LOC) due to distortion of the ascending arousal systems as they pass through the midbrain]

 A dilated pupil from in the absence of a LOC is not due to uncal herniation


Describe the major symptoms that characterize bleeding in the subdural, epidural and
subarachnoid spaces.

Epidural hematoma:

From trauma to the skull: usually from middle meningeal artery.
• May also be from sinuses (~15%).
•“Lens shaped” structure on MRI
• Often has period of lucidity before severe symptoms (from a brain herniation).

Subdural Hematoma:
Horizontal (axial) MRI showing crescent-shaped subdural hematoma due to tearing of bridging veins, which often occurs during rapid accelerations. Symptoms may progress over longer periods.
-common in elderly

Subarachnoid hemorrhage: bleeding into the subarachnoid space usually secondary to head trauma.
• Usually traumatic
-["Non-traumatic” from bleeding from an A-V malformation or ruptured aneurysm.

A burst aneurysm is responsible for 80% of non-traumatic subarachnoid hemorrhages. • Aneurysms form when the vessel wall is weakened, and can burst
under conditions of increased
• Most aneurysms occur in the
“anterior circulation” supplied by
the internal carotid artery.

The classic presentation is sudden-onset, severe headache (from blood irritating meninges) "worst headache of my life"

Subarachnoid is diagnosed by bloody CSF


Define hydrocephalus and the types of hydrocephalus and potential causes.


Condition of excess CSF

1- excess production (choroid plexus tumors)

2- obstructed flow anywhere in ventricles or subarachnoid space (tumors, malformations, hemorrhage)

3- decreased reabsorption via arachnoid granulations.

“Communicating hydrocephalus”: lateral ventricles communicate with subarachnoid space.

“non-communicating hydrocephalus”: flow obstructed within
the ventricular system.

Children and Adults:
-Headache (especially in the morning)*
Decreased cognitive function
Neck pain
Vomiting (especially in the morning)* Blurred vision (papilledema) Drowsiness
Failure of upward gaze

*CSF is less reabsorbed when lying down.


What is the presentation of children with hydrocephalus? \Signs and symptoms


-rapid head growth
-bulging fontanelle in infants held upright
-dilated scalp veins

-downward eyes
-poor feeding

ventriculoperitoneal shunt:
can relieve chronic hydrocephalus. Surgeons insert tubes that let the cerebrospinal fluid drain out of the brain into the abdomen, where the body reabsorbs it. These tubes, under a child’s skin, can prevent brain damage..


Chiari I

-the most common
Congenital hindbrain anatomic anomalies associated with the downward displacement of the cerebellum,
brainstem or craniocervical junction.
-produce hydrocephalus

Cerebellar tonsils
below the foramen

2. Syringomyelia (Chiari is most common cause) Syringomyelia is the development of a fluid-filled cyst (syrinx) within your spinal cord. Over time, the cyst may enlarge, damaging your spinal cord and causing pain, weakness and stiffness, among other symptoms.
3. Compression of brainstem

Most common symptoms are
• Headache (increased intracranial
• Ataxia (cerebellar dysfunction),
• Impaired movement (brainstem


Chiari II (Arnold Chiari malformation)

Less common

Significant herniation through foramen magnum
cerebellar tonsils and vermis lower brainstem
• Causes aqueductal stenosis
and Hydrocephalus.
• Usually with
meningomyocele - Meningomyelocele is a type of spina bifida. Spina bifida is a birth defect in which the spinal canal and the backbone don’t close before the baby is born. This type of birth defect is also called a neural tube defect.

The spinal cord and the meninges (the tissue that covers the spinal cord) may actually protrude through the child’s back. In some cases that skin covers the spinal cord and meninges, it may also stick through the skin. - syrinx in base of spinal cord


Normal Pressure Hydrocephalus
His grave is dug

-occurs in the elderly

Classic triad of symptoms

Dementia (of varying degrees)

Urinary incontinence: May present as urgency, frequency, or a diminished awareness of the need
to urinate

Gait disturbance: Usually the first symptom; magnetic gait. :


May be related to impaired reabsoprtion from meningitis or subarachnoid hemorrhage


Define radiculopathy and causes

.damage to a spinal nerve
The most common pathology to spinal nerves are herniated discs.
-Osteophytes can also cause radiculopathy
-spinal stenosis - hypertrophy of ligamentum flavum
-Foramen stenosis-hypertrophy of facet

Typical Symptoms related to radiculopathy
1. Burning, tingling pain that radiates from the back along
a. “lancinating” or stabbing pain
b. Location, location, location 2. Numbness (anesthesia, analgesia)
a. possible, but there is overlap in dermatomes.
b. analgesia, tested with a pinprick may be more sensitive 3. Worsening of symptoms with coughing, sneezing, straining.
Flexing the head in the case of cervical radiculopathy.
4. Muscle weakness
***5. T1 radiculopathy can cause a Horner’s syndrome, because it
interrupts the sympathetic pathway to the eye.
a. constricted pupil (miosis)
b. anhidrosis (decreased sweating) of the skin of the face
c. ptosis (drooping) of the eyelid


Describe the features of spinal shock.

Spinal Cord injury causes immediate flaccid paralysis: Spinal Shock

This is because descending influences are interrupted immediately. After that there is a loss of motor and autonomic function from the lesion down.

Following a spinal cord injury, there is a loss of all motor and autonomic function below the lesion.
flaccid paralysis bowel and bladder paralysis loss of vasomotor tone (hypotension)
The period of time is usually 1-6 weeks. The mechanism is thought to be a loss of descending facilitation that keeps the spinal cord circuits in a continual state of activation/readiness.


Horner's syndrome

T1 radiculopathy can cause a Horner’s syndrome, because it
interrupts the sympathetic pathway to the eye.
a. constricted pupil (miosis)

b. anhidrosis (decreased sweating) of the skin of the face

c. ptosis (drooping) of the eyelid


Chiari 1 vs Chiari 2

Chiari 1:
Findings typically asymptomatic in children
abnormally shaped cerebellar tonsils are downwardly displaced through the foramen magnum
Associated condition: syringomyelia

Chiari 2:
Findings typically symptomatic
cerebellar vermis and tonsil are
downwardly displaced through the foramen magnum
Associated condition
spinal meningomyelocele


Fetal alcohol spectrum disorder

Fetal alcohol spectrum disorder (FASD) shows that there is a link between maternal alcohol ingestion and a range of birth defects, including intellectual disability and growth deficiencies/structural abnormalities of the brain, such as microcephaly (small head size) and holoprosencephaly (failure of forebrain to form separate cerebral hemispheres with associated midline facial defects), face (small midface and eyes, low nasal bridge and short nose, smooth philtrum and thin upper lip), and heart (including ASD, VSD).

Fetal alcohol syndrome (FAS) is on the severe end of FASD. There is no known safe amount or time period to drink alcohol during pregnancy because although abnormalities may sometimes not be evident with minimal alcohol consumption, it may cause behavioral issues.


Dandy-Walker syndrome

In individuals with the rare Dandy-Walker syndrome, there is congenital malformation of the cerebellum, which may result from cystic enlargement of the 4th ventricle and leads to developmental delays, defective muscle tone, poor coordination and balance (ataxia), and sometimes hydrocephalus.


Spinal Muscle Atrophy (SMA I-IV)

Describe the clinical features and pathophysiology of Werdnig-
Hoffman disease

A group of diseases caused by degeneration of the anterior horns.

These are progressive and begin in infancy.

Due to abnormalities in chromosome 5
Motor neurons are affected in the spinal cord and cranial nerve motor nuclei
Most common (and severe) type of spinal muscle atrophy is SMA I Werdnig-Hoffmann disease
“acute infantile spinal muscle atrophy”
__________ _________
autosomal-recessive inheritance pattern “floppy-baby” median age of death is 6-7 months. affects 1/10,000 lives births
Weakness and muscle wasting in
-bulbar muscles:
sucking, swallowing, breathing
Pathological changes that occur with sustained lower motor neuron disease: e.g., polio, peripheral neuropathies.


Describe apraxia and how to test for it.

Results from lesions to Premotor cortex or Posterior Parietal cortex

Would be contralateral apraxia, difficulty in using body part to perform complex voluntary actions.

Tested by asking patients to do tasks such as grasping a pencil, even though there is no obvious, weakness, paralysis, or altered tone. Affects complex movements such as buttoning.


Compare the upper motor neuron and lower motor neuron syndromes.


Weakness: Yes in both (only similarity)

Atrophy: Only in LMN, mild from disuse in UMN.

Fasciculations: Only in LMN

Reflexes: Increased in UMN, decreased in LMN

Tone: Increased in UMN, decreased in LMN


Define hyperreflexia, clonus, hypertonia, spasticity clinically and physiologically.

Spasticity: (vestibulospinal and reticulospinal > reflex excitability)
1. UMN damage disturbs the balanced modulation of spinal cord interneurons and motor neurons by descending pathways (+ and -).
• Removing any of these inputs changes the balance of excitability of motor neurons and reflexes
2. Loss of inputs to motorneurons produces neuroplastic changes in motor neurons: denervation supersensitivity and sprouting from local interneurons.
3. Reduced muscle extensibility due to muscle contracture >increased muscle spindle activation.

Clonus: Occurs with severe hyper-reflexia: oscillation when the muscle is rapidly stretched and then held at a constant length.

Velocity-dependent: less resistance to slow movement compared to fast
Clasp-knife response: initial resistance followed by inhibition of the muscle (possibly due to golgi-tendon response)


Differentiate between the symptoms of Bell’s palsy and a corticobulbar tract

Corticobulbar tract lesion:
Exceptions to compensation:
1- lower nucleus of VII. These go to the lower face.
2- mostly contralateral to CN XII (motor neurons to the tongue.)
Lesions to one corticobulbar tract produce the following deficit:
1- Paralysis to contralateral lower face. 2- Some paralysis to the opposite tongue, and difficulty swallowing (dysphagia).

Bell's palsy:
-Right Cranial nerve VII lesion (Bell’s palsy) causes lower motor neuron paralysis of ½ the face.
Both upper and lower face affected on right or left

-corticobulbar is only contralateral lower face


Recognize decorticate and decerebrate rigidity.

Decorticate - lesion ABOVE midbrain
-upper limb: flexed - elbow, finger
-lower limb: extended: knee

Decerebrate - lesion BELOW midbrain All limbs extend


Discuss some of the common causes of upper motor neuron syndromes.

Trauma: Head injury or spinal cord injury

Stroke: In cortex, internal capsule, ventral pons, spinal cord (sudden onset)

Multiple Sclerosis: Autoimmune/inflammatory disease that affects myelin pathways in the central nervous system. Symptoms separated in time and space.

Amyotrophic Lateral Sclerosis: Degenerative disease of upper and lower motor neurons. Also called Motor neuron disease, Charcot’s disease or Lou Gehrig’s disease. Characterized by fasciculations, weakness, and spasticity. Rapid progression, resulting in death in 2-3 years.


What are the *unique signs of upper motor neuron lesions?

-hyperreflexia - thought to be because the muscle becomes super sensitive without period stimulation from UMN so you get a really strong sensory response at the level

-Clonus - rhythmic contractions of antagonist muscles- lets say you flex at the ankle joint, pt with UMN injury will be sent into involuntary movements of up and down.

-Hypertonia - when a doctor moves the leg around, there is more resistance, instead of relaxed like LMN

-Extensor Plantar response aka Babinski sign : if you take a hard object, scrape up along bottom foot, normal plantar response is flexor.


Cerebral Palsy - a review

A variety of non-progressive neurological disorders that appear in infancy or early childhood and permanently affect body movement and muscle coordination.

Ischemia at birth

Cerebal Palsy Presentation:
1: Some degree of motor impairment
2: An insult to the developing brain
3: Intellectual disability in ~50%


Distinguish between pathology of myelin sheaths
or axons.

3 types

1. Wallerian degeneration: axonal damage leads to "dying forward".
-distal axon degeneration
-Chromatolysis of cell body, nucleolus expands and moves to cell membrane, Nissil substance disintegrates
-Recruit macrophages distal to lesion

2. Axonal degeneration:
Conditions that affect the health of neurons such as metabolic disease leads to "dying back" of axons. Loss of myelin CAN accompany this process.
**LONGER axons are affected FIRST, resulting in distal extremities being affected first - (diabetic neuropathy)

3. Segmental demyelination: occurs when sheaths are damaged by trauma or disease. Myelin may be affected secondarily to axonal death
-Symptoms are detected by nerve conduction tests - conduction block or slow
-Myelin and conduction can return in days to weeks

*Only 1 & 2 result in muscle atrophy


• Distinguish between different types of neuropathy.

Mononeuropathy multiplex

When symptoms follow a nerve root pattern, (dermatome OR myotome) it is referred to as a radiculopathy. Often caused by compression of nerve roots from protruding discs.
ex. A herpes zoster infection arising in the sensory neurons of the dorsal root ganglion of T1
spinal nerves, may produce just sensory symptoms
(pain) at the T1 dermatome (usually unilateral).

When symptoms follow a peripheral nerve it is referred to as a mononeuropathy, often caused by injuries - ex carpal tunnel , sensory, motor and autonomic components distal to wrist

Mononeuropathy multiplex: Mononeuritis multiplex is a painful, asymmetrical, asynchronous sensory and motor peripheral neuropathy involving isolated damage to at least 2 separate nerve areas. Multiple nerves in random areas of the body can be affected. As the condition worsens, it becomes less multifocal and more symmetrical. Mononeuropathy multiplex syndromes can be distributed bilaterally, distally, and proximally throughout the body

Plexopathy: unlike mononeuropathy, this is lesion of a network of nerves. The region of nerves it affects are at the brachial or lumbosacral plexus. Symptoms include pain, loss of motor control, and sensory deficits.

Polyneuropathy: is damage or disease affecting multiple peripheral nerves (peripheral neuropathy) in roughly the same areas on both sides of the body, featuring weakness, numbness, and burning pain.
-show a distal and symmetric sensorimotor (maybe autonomic) distribution. Sometimes called glove and stocking pattern. Most common causes are diabetes, alcohol, hypothyroidism, vit B12 deficiency.


What would be the presentation with these losses

Peripheral nerve
Small fibers
Sensory ganglia lesions

Peripheral: contains all fiber types > sensory, motor and autonomic

Small fiber: mostly sensory so > pain, temperature, and autonomic loss

Myelin > large fibers responsible for vibration and position sense: with some motor loss

Sensory ganglia> only sensory symptoms


Diabetic neuropathy
1.9% of population,

30% of diabetics
16% have chronic neuropathic pain
-greatest source of morbidity and mortality in diabetes patients - implicated in 50-75% of all amputations.

-Length dependent diabetic polyneuropathy accounts for >80% of patients with diabetic neuropathy.
Symptoms begin in the feet, then move to more proximal legs and distal upper limbs. (most nutritional, metabolic and toxic diseases produce this pattern of distal neuropathy)

Patho: Axonal dying back, degeneration and demyelination occurs
-includes effects related to ischemia, oxidative stress and inflammatory processes
-SENSORY (as with all distal neuropathies) are MORE affected than motor. The sensory deficits involve most small UNmyelinated and myelinated fibers ("small fiber polyneuropathy")

Symptoms: paresthesias (tingling or prickling sensation), dysesthesias (impairment of sensitivity especially to touch).
Can lead to trophic changes like calluses and plantar ulcers.

Histo: decreased number of myelinated and unmyelinated axons
-thickening of walls of blood vessels


Vit B12 deficiency

-most common metabolic neuropathy

Symptoms: distal limbs - beginning more commonly in the upper limb instead of the feet like diabetics.
**Loss of vibration sense is most common feature.
-also pain numbness and tingling in hands or feet, sensory loss and motor weakness

Subacute combined degeneration:
May primarily or secondarily affect lateral and dorsal columns of the spinal cord. Therefore ataxia and spasticity can occur together with symptoms of peripheral neuropathy.

Without B12 myelin production is abnormal
Diagnosis: *NCV will decrease


Guillain Barre

-most common cause of acute paralysis in clinical practice.

-acute inflammatory demyelination polyneuropathy (another name)

-mostly rapidly progressing and potentially fatal form of neuropathy
-most of the time, GB begins 1-3 weeks after infection or vaccination, ex: campylobacter jejuni, herpesvirus. -Infection causes an autoimmune/inflammatory attack on peripheral myelin.

This time, MOSTLY MOTOR> ascending Symmetrical paralysis

May begin with paresthesias in toes and fingers with aching in thighs and back. Ascending paralysis that can (if severe) affect breathing and require respiratory support.

Diagnosis: Nerve conduction velocity is decreased
-Albuminocytologic dissociation - increased protein in CSF with normal cell count


Charcot-Marie-Tooth Disease
"hereditary motor and sensory neuropathy"

Group of several hereditary diseases that either affect myelin (CMT1) or axons (CMT2) directly.
CMT1 is most common, produces a motor sensory neuropathy.
-primarily affects distal muscle, particularly the peroneal nerve
-because of demyelination, small fiber types carrying pain and temperature are not affected
-frequently occurs with pes cavus and hammertoes *true for all CMT

-typical onset is late childhood, identifiable by slowly progressive nature and reduced conduction velocity in all nerves


What is a Romberg test

Romberg's test, Romberg's sign, or the Romberg maneuver is a test used in an exam of neurological function for balance, and also as a test for drunken driving. The exam is based on the premise that a person requires at least two of the three following senses to maintain balance while standing: proprioception (the ability to know one's body position in space); vestibular function (the ability to know one's head position in space); and vision (which can be used to monitor and adjust for changes in body position).

A patient who has a problem with proprioception can still maintain balance by using vestibular function and vision. In the Romberg test, the standing patient is asked to close his or her eyes. A loss of balance is interpreted as a positive Romberg's test.


What would each of these lesions feel like?
1. Parietal lobe/primary sensory cortex

2. Thalamus


4. STT

5. Nerve root

Lesion of parietal lobe or primary sensory cortex: -Contralateral numb tingling or pain

Lesion of thalamus:
-Contralateral burning pain = Dejerine-Roussy (Thalamic/Central) Syndrome

Lesion of dorsal column medial lemniscus (DCMLS):
-Tingling, numb sensation
-Tight band-like sensation around the trunk or limbs
-Feeling of having gauze on fingers
-Electricity sensation down back and extremities upon neck flexion = Lhermitte ’s sign (if lesion is cervical)

Lesions of anterolateral (spinothalamic STT) pathways
Sharp, burning or searing pain

Lesion of nerve roots
-Radicular pain with numbness and tingling in dermatomal distribution = radiculopathy


What are these mechanical causes of sensory neuropathys

Neurapraxia: mild insult - temporary impairment of nerve conduction

Wallerian degeneration: severe insult - degeneration distal to site of injury but regeneration may occur

Causalgia/Complex regional pain syndrome: incomplete regeneration - burning sensation, edema

Neuralgia = severe persistent pain in the distribution of a cranial or spinal nerve. Usually contralateral and episodic.


What are CIP, inherited erythromelalgia, and PEPD

Recessive mutations causing loss of function – congenital insensitivity to pain (CIP)

Dominant mutations causing gain of function – inherited erythromelalgia (IEM) - sensitivity to temperature

Paroxysmal extreme pain disorder (PEPD) - rare disorder whose most notable features are pain in mandibular, ocular and rectal areas.


What is the progression of spinal cord injury?

Tissue disruption: Primary cell death, breaking of axons, etc.
• Injured spinal cords show progressive
tissue loss.
• Central hemorrhage necrosis develops over 2-3 hours.
• White matter blood flow falls by 50% by 3 hours.
• Metabolism is compromised with high
lactic acid levels.

Rapid entry of calcium ions into cells and swelling.
• Intracellular calcium activity >1µM
activates proteases and phospholipases,
breaking down proteins and lipids.
• Ca binds to mitochondria and produces free radicals.


What would be the presentation of complete cord

Loss of sensory, motor, reflex and autonomic function below lesion. Acute onset causes spinal shock

1. fracture/dislocation trauma by MVA, dive in pool, fall off horse, etc, usually in the cervical region, or bullet/knife wound
2. demyelinating disease- MS, post-infectious transverse myelitis
3. compression by tumor or inflammatory mass
Rate: Helps identify etiology; acute versus slowly evolving
An acute syndrome elicits spinal shock, which can last several weeks, and consists of loss of all sensation, flaccid paralysis, loss of reflexes, and no bowel/bladder function.

Chronically, there will emerge
-hyper-active reflexes (clonus)
- increased tone
-Babinski sign
which together we term spasticity. Over time there will be flexor spasms, set off by simple cutaneous stimulation, and later automatic bladder emptying that occurs after it fills. If the lesion is sacral, the bladder will distend and overflow causing emptying with chronic infection.


Presentation of Brown Sequard syndrome.

Ipsilateral to lesion: weakness, increased tone, and hyperreflexia, paresthesia, proprioceptive loss, root pain.

Contralateral to lesion: loss of pain and thermal sense

*Dissociated sensory loss
Spinal hemisection- example, C4 level

Ipsilateral corticospinal tract- UMN syndrome
-weakness of arm and leg mild atrophy -hyper-reflexia (clonus of ankle),
-Babinski sign loss of abdominal and anal wink

Ipsilateral posterior (dorsal) column- position and vibration

Contralateral loss of pain (pin), temperature

Autonomics- Horner's syndrome (miosis, ptosis, anhydrosis)

C4 level exhibits complete loss of motor and sensory root functions-
including sensation in dermatomal pattern if 2 roots, reduced C4 muscle (LMN) innervation (function).


Describe the cause of Horner's syndrome

Horner's syndrome results when the cervical sympathetic pathway from the hypothalamus is interrupted. The lesion may be central, preganglionic, or postganglionic in origin. It may be primary or secondary to another disorder. Symptoms may include ptosis, miosis, anhydrosis or hyperemia. (flushed skin)


Partial Compression- extra-axial pain presentation and the progression - Growing mass

C6-C7 Extramedullary Compression (Mass from the Outside)
• Dorsal root compression: pain and paresthesias, loss of pin, temperature, position, and vibration in C6/C7 dermatome; reduced triceps reflex •Dorsal column compression: ipsilateral loss of position and vibration on arm and upper torso
•Corticospinal tract compression: ipsilateral UMN signs: increased tone and reflexes in triceps (not biceps), knee, and ankles with Babinski sign •Ventral horn compression: Loss of ipsilateral lower motor neurons: segmental muscle weakness


Central cord lesion presentation

Syringomyelia/Central Cord Syndrome

Cavitation near the central canal of the spinal cord
Causes- developmental, vascular (AVM), trauma, infections, astrocytic tumor, congenital malformations.

Most commonly occur from C3 to T4.
Example: C4-C8
1. Initially experience a cape (shawl) distribution of lost spinothalamic fibers crossing at the ventral commissure, giving rise to reduced pin and temperature over lateral arms, forearms and fingers.
2. As it expands, will include shoulders, back and anterior thorax, but preservation of dorsal columns.
3. Further expansion into the ventral horn compromises ventral motoneurons, yielding LMN flaccid weakness of shoulders, arms, forearms and hands.
4. Finally, expansion into lateral funiculus interrupts descending corticospinal tracts, with UMN syndrome. Thus early on there is a segmental loss of sensory and motor pathways, whereas later, all functions below the lesion are effected except those most peripherally localized, giving rise to *sacral sparing.


ALS presentation

-Atrophic weakness of hands/forearms;
-spasticity of legs;
-generalized hyperreflexia;
-a mixed UMN and LMN disorder progressive spread both rostrally and caudally until fatal
-LMN signs with loss of strength, reduced tone, atrophy and loss of reflexes, all due to muscle denervation.

Some of these signs are apparently reversed by appearance of hyper-reflexia from loss of UMN innervation.

Most common initial symptoms: stiffness/weakness and muscle wasting of hands/fingers, hand cramping, and later twitching of forearms (fasciculations)
Only upper and lower motor neurons affected, no sensory involvement


Subacute Combined Degeneration

Subacute Combined Degeneration
-Vit B12 deficiency (macrocytic anemia)
-Dorsal columns are most affected, corticospinal tract next

-Gradual onset with symmetric sensory loss
Because B12 deficiency also causes peripheral neuropathy, there may be the paradoxical combination of extensor plantar reflex (UMN sign) and hypoactive ankle DTR (LMN sign)


what would each of these lesions feel like?

parietal lobe or primary sensory cortex
dorsal column medial lemniscus
Anterolateral STT pathways
Nerve roots

-contralateral numb tingling or pain

-contralateral burning pain = Dejerine-Roussy (Thalamic/Central) syndrome

-DCMLS - tingling numb sensation, tight band like sensation around the trunk or limbs, feeling of having gauze on fingers, electricity sensation down back and extremeties upon neck flexion

STT-sharp burning or searing pain

Nerve roots- radicular pain with numbness and tingling in dermatomal regions


Which sensory pathways are disturbed by MS?

Ascending pathways: cuneatus, gracilis

Dorsal spinocerebellar tract
Ventral spinocerebellar tract
Anterolateral system -spinothalamic


How does a syringomyelia/Central cord syndrome present


1. Loss of spinothalamics crossing at the ventral commissure: initially experience a cape, shawl distribution, giving rise to reduced pain and temperature sensation over lateral arms, forearms and fingers

2. Expands to include shoulders, back and anterior thorax, sparing the dorsal column

3. Further expansion into ventral horn fucks up LMN, leading to LMN flaccid weakness of shoulder, arms, forearms and hands.

4. Expansion into the lateral funiculus interferes with corticospinal tracts with UMN syndrome.

Segmental loss of sensory and motor pathways> all functions (pain, temp, vibration, position, motor) below the lesion are affected except for those most peripherally localized = sacral sparing.


How would an expanding herniated disc present

1. Dorsal root compression: pain and paresthesias, loss of pain, temperature, position and vibration in the dermatome. Reduced triceps reflex (example is C6-C7)

2. Dorsal column compression (cuneate) ipsilateral loss of position and vibration on arm and upper torso

3. Corticospinal tract compression: ipsilateral UMN signs, increased tone and reflexes in triceps, knee, and ankles with babinski sign

4. Ventral horn compression: loss of ipsilateral lower motor neurons, segmental muscle weakness.


Stroke in the right internal capsule, what is the presentation on the person?

On the LEFT side

-head tilted towards the left
-paresis of lower facial muscles
-elbow flexed
-forearm pronated
-fingers flexed
-hip circumducted
-knee extended
-foot plantar flexed


What would a lesion of the corticobulbar tract present with?

1. Paralysis to contralateral lower face

2. Some paralysis to opposite tongue, and difficulty swallowing (dysphagia)


Co-deletion of 1p and 19q

Oligodendroglioma WHO grade 2 or 3. Usually cerebral hemispheres and often hemorrhagic.


Symptoms of pituitary adenoma

*bitemporal hemianopsia

Hormone overproduction

1. Prolactin: amenorrhea, galactorrhea: milky nipple discharge unrelated to the normal milk production of breast-feeding.

2. Growth hormone - acromegaly

3. ACTH- Cushing's Disease


Squamous epithelium, "wet keratin", cholesterol clefts.

Craniopharyngioma - in very young kids think this not adenoma.


Neurofibromin function and loss results

Neurofibromin (NF1) negatively regulates the Ras oncoprotein.

Causing tumors
- neurofibromas
-cafe au lait spots
-optic gliomas
-malignant peripheral nerve sheath tumor


Bilateral vestibular schwannoma, what is the underlying genetic condition?

Neurofibromatosis type 2

-additionally meningioma 50% of cases and ependymoma

Encodes for Merlin which links proproliferation signals with underlying actin cytoskeleton.


Antoni A, B and Verocay bodies



Whorls, psammatous calcifications



Acne that won't go away, renal angiomyolipoma

Mutation in TSC1 or TSC2 which regulate mTOR. Tuberous sclerosis complex, would also have subependymal giant cell astrocytoma.


Foamy stromal cells and dense capillary network

Hemangioblastoma - Von Hippel Lindau mutation leading to constitutive activation of HIF, leading to overproduction of angiogenic growth factors .


Grade 4, synaptophysin positive. True rosette

medulloblastoma, normal neurons are synaptophysin negative.


Frequent amplification of receptor tyrosine kinases (EGFR)

Glioblastoma (diffuse astrocytoma grade IV)


Keywords Glioblastoma

-palisading necrosis
-butterfly lesion
-microvascular proliferation
-MGMT methylation
-gadolinium, ring enhancing lesion.


Which tumors are associated with NF2 mutation

1. Schwannoma 100%
2. Meningioma 50%
3. Ependymoma


Which pathways are typically effected in the following

Tabes dorsalis: tertiary syphilis

Multiple sclerosis

Anterior spinal artery

Subacute Combined degeneration (B12)


Central cord

Extramedullary compression

Multiple sclerosis:
1. Dorsal column,
2. CST
3. Cerebellar tracts (ataxia, dysmetria: inability to judge distance or scale of movements, nystagmus: rapid involuntary movements of eyes, dysarthria: slurred speech)

Anterior spinal artery:
1. no dorsal column
2. CST (anterior and lateral)
3. Cerebellar tracts

B12 deficiency:
1. dorsal columns MOST affected
2. CST
3. Cerebellar tracts
4. Peripheral nerve
(UMN > LMN, in this order)

ALS: motor only! (compare to B12)
1. Peripheral nerves
2. CST
3. no sensory involvement

Central cord: (cervical usually)
1. spinothalamic (shawl)
1. Spinothalamic (shawl)
2. Ventral horns (LMN)
3. CST (with sacral sparing)
4. Can include dorsal column

Extramedullary Compression:
1. Dorsal root (reduced triceps reflex)
2. Dorsal column compression
3. CST
4. Ventral horn compression


What are LMN only disease

-floppy baby
-weakness and muscle wasting in limbs
-respiratory bulbar muscles - sucking, swallowing, breathing

Polio - attacks ventral horn
-new sprouts compensate
-post-polio period occurs years later