Neurology Flashcards
What is the glasgow coma scale?
When there are different motor responses on each side, the best motor response is used for scoring.
What is status elipticus?
Status epilepticus is a medical emergency that refers to a prolonged seizure or a series of seizures without full recovery of consciousness between them. Specifically, it is defined as:
A seizure lasting more than 5 minutes.
Two or more seizures occurring without the person regaining full consciousness between them.
What is the management of status elipticus?
ABC
airway adjunct
oxygen
check blood glucose
First-line drugs are benzodiazepines
in the prehospital setting PR diazepam or buccal midazolam may be given
in hospital IV lorazepam is generally used. This may be repeated once after 5-10minutes
If ongoing (or ‘established’) status it is appropriate to start a second-line agent such as levetiracetam, phenytoin or sodium valproate
NICE state ‘Take into account that levetiracetam may be quicker to administer and have fewer adverse effects than the alternative options.’
If no response (‘refractory status’) within 45 minutes from onset, then the best way to achieve rapid control of seizure activity is induction of general anaesthesia or phenobarbital
What are the complications of meningitis?
Neurological sequalae
sensorineural hearing loss (most common)
seizures
focal neurological deficit
infective
sepsis
intracerebral abscess
pressure
brain herniation
hydrocephalus
Patients with meningococcal meningitis are at risk of Waterhouse-Friderichsen syndrome (adrenal insufficiency secondary to adrenal haemorrhage).
What is the most common complication of meningitis?
Sensorineural hearing loss
What lumbar puncture results suggest meningitis?
High white cell count, high protein and low glucose which are the typical findings of bacterial meningitis.
There is also the high opening pressure and the cloudy CSF which suggest infection.
What is hoffmans sign?
Hoffmann’s sign is a pathological reflex where the thumb and index finger of the patient involuntarily flex when the examiner gently flicks or taps the nail of the middle finger (or sometimes the thumb) in a downward direction. indicate the presence of upper motor neuron dysfunction
What is Degenerative cervical myelopathy?
Degenerative cervical myelopathy (DCM) is a progressive neurological condition caused by spinal cord compression in the cervical spine (the neck region) due to degenerative changes in the spine.
What are the symptoms of DCM?
DCM symptoms can include any combination of [1]:
Pain (affecting the neck, upper or lower limbs)
Loss of motor function (loss of digital dexterity, preventing simple tasks such as holding a fork or doing up their shirt buttons, arm or leg weakness/stiffness leading to impaired gait and imbalance
Loss of sensory function causing numbness
Loss of autonomic function (urinary or faecal incontinence and/or impotence) - these can occur and do not necessarily suggest cauda equina syndrome in the absence of other hallmarks of that condition
Hoffman’s sign: is a reflex test to assess for cervical myelopathy. It is performed by gently flicking one finger on a patient’s hand. A positive test results in reflex twitching of the other fingers on the same hand in response to the flick.
Kernigs sign?
Kernigs sign refers to painful knee extension, from a position of hip flexion and knee flexion. It suggest meningeal irritation e.g. meningitis, subarachnoid haemorrhage.
Straight leg raise: this is positively associated with radicular pathology such as disc herniation. The patient feels pain in the back when the leg is raised between 30-60 degrees.
The ankle brachial pressure index [ABPI] is a simple method of assessing the peripheral circulation. It is calculated by dividing systolic blood pressure in the ankle by the the systolic blood pressure in the arm. These are equal in health (ABPI = 1). The ABPI is reduced in peripheral vascular disease.
Tinels test includes tapping over the volar surface of the wrist joint i.e. over the carpal tunnel. This can reproduce paraesthesias in patients with carpal tunnel syndrome.
Limited external rotation of the shoulder 73%
This patient is likely to have adhesive capsulitis. Patients have global restriction of shoulder movements, in at least two axes, though external rotation is classically described as the most affected and painful.
Features of Brown sequard syndrome
Unilateral spastic paresis and loss of proprioception/vibration sensation with loss of pain and temperature sensation on the opposite side
Tracts affected
1. Lateral corticospinal tract
2. Dorsal columns
3. Lateral spinothalamic tract
- Ipsilateral spastic paresis below lesion
- Ipsilateral loss of proprioception and vibration sensation
- Contralateral loss of pain and temperature sensation
How does idiopathic intercrainal hypertension present?
The patient presents with a chronic headache that worsens in the morning and upon coughing or straining, which suggests elevated intracranial pressure. A CT scan of the head rules out a mass lesion. Clinical examination confirms papilloedema. Given her multiple risk factors for idiopathic intracranial hypertension’including contraceptive pill use, age, gender, and weight’this is the most likely diagnosis.
Features
headache
blurred vision
papilloedema (usually present)
enlarged blind spot
sixth nerve palsy may be present
What are the risk factors for Idiopathic intercranial hypertension?
Risk factors
obesity
female sex
pregnancy
drugs
combined oral contraceptive pill
steroids
tetracyclines
retinoids (isotretinoin, tretinoin) / vitamin A
lithium
What is the management of Idiopathic intercranial hypertension?
Management
weight loss
whilst diet and exercise are important, medications such as semaglitide and topiramate may be considered by specialists. Topiramate is particularly beneficial as it also inhibits carbonic anhydrase
carbonic anhydrase inhibitors e.g. acetazolamide
topiramate is also used, and has the added benefit of causing weight loss in most patients
repeated lumbar puncture may be used as a temporary measure but is not suitable for longer-term management
surgery: optic nerve sheath decompression and fenestration may be needed to prevent damage to the optic nerve. A lumboperitoneal or ventriculoperitoneal shunt may also be performed to reduce intracranial pressure
What is normal pressure hydrocephalus?
Normal pressure hydrocephalus is a reversible cause of dementia seen in elderly patients. It is thought to be secondary to reduced CSF absorption at the arachnoid villi. These changes may be secondary to head injury, subarachnoid haemorrhage or meningitis.
What is the classical triad seen in normal pressure hydrocephalus?
A classical triad of features is seen
urinary incontinence
dementia and bradyphrenia
gait abnormality (may be similar to Parkinson’s disease)
It is thought around 60% of patients will have all 3 features at the time of diagnosis. Symptoms typically develop over a few months.
What is seen in imaging of normal pressure hydrocephalus?
hydrocephalus with ventriculomegaly in the absence of, or out of proportion to, sulcal enlargement
What is the management of normal pressure hydrocephalus?
Management
ventriculoperitoneal shunting
around 10% of patients who have shunts experience significant complications such as seizures, infection and intracerebral haemorrhages
What is Spastic paraparesis?
Spastic paraparesis describes a upper motor neuron pattern of weakness in the lower limbs
What are the causes of Spastic paraparesis?
Causes
demyelination e.g. multiple sclerosis
cord compression: trauma, tumour
parasagittal meningioma
tropical spastic paraparesis
transverse myelitis e.g. HIV
syringomyelia
hereditary spastic paraplegia
osteoarthritis of the cervical spine
What is amaurosis fugax?
amaurosis fugax means ‘transient darkening’ and it is used by doctors to describe a temporary loss of vision through one eye, which returns to normal afterwards. This is usually due to a temporary disturbance of the blood flow to the back of the eye.
What are the feautures of Internuclear ophthalmoplegia?
impaired adduction of the eye on the same side as the lesion
horizontal nystagmus of the abducting eye on the contralateral side
What is typically spared in motor neuron disease?
Motor neurone disease (MND), also known as amyotrophic lateral sclerosis (ALS), occurs when motor neurons in the brain and spinal cord degenerate. This typically leads to progressive weakness of limb, respiratory, and bulbar musculature.
The extraocular muscles are seemingly preserved in most MND patients, even until the terminal stage. Notably, eye movements and blinking are usually the last modes of communication available to terminal MND patients. The eye muscles appear to be better equipped to maintain their muscle-nerve contacts and are thereby less affected.
What are the clues which point towards a diagnosis of motor neuron disease?
asymmetric limb weakness is the most common presentation of ALS
the mixture of lower motor neuron and upper motor neuron signs
wasting of the small hand muscles/tibialis anterior is common
fasciculations
the absence of sensory signs/symptoms
vague sensory symptoms may occur early in the disease (e.g. limb pain) but ‘never’ sensory signs
Other features
doesn’t affect external ocular muscles
no cerebellar signs
abdominal reflexes are usually preserved and sphincter dysfunction if present is a late feature