Neurology (2) Flashcards

Question

Summarise the aetiology of motor neurone disease

Answer 1

Unknown Thought to be free radical damage and glutamate excitotoxicity Genetic predisposition - SOD1 mutation on chromosome 21 Motor neurone degeneration

Answer 2

Men affected more (3:2) Average age of presentation 60 years old 5-10% have family history in autosomal dominant inheritence

Answer 3

``` Muscle weakness Muscle fasciculation Dysarthria Dysphagia Weak grip - difficulty turning door handle Weak shoulder abduction - difficulty washing hair Foot drop Proximal myopathy Stumbling spastic gait ```

Answer 4

UMN signs - hyperreflexia, spastic paralysis, weakness, upgoing plantars LMN signs - weakness, fasciculations, atrophy, absent reflexes

Answer 5

No diagnostic investigation EMG - denervation features Nerve conduction - normal Brain/spine MRI - exclude structural cause Lumbar puncture - exclude infectious aetiology Bloods - CK, ESR, anti-GMI ganglioside antibodies elevated

Answer 6

A tendency to recurrent, unprovoked and unpredictable seizures (a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous activity in the brain) Types of seizures: Partial - only affect part of the brain Simple partial seizure - consciousness not affected Complex partial seizure - consciousness affected ``` Generalised - affect both hemispheres and consciousness Atonic Tonic-clonic Myoclonic Absence Tonic Clonic ```

Answer 7

Increased excitation Decreased inhibition ``` Idiopathic Secondary: Tumour Stroke Infection Injury Inflammation (MS, vasculitis) Toxic/Metabolic (sodium imbalance) Drugs (alcohol withdrawal, benzodiazepine) Vascular (haemorrhage, infarction) Malignant HTN or eclampsia Congenital abnormalities (cortical dysplasia) Neurodegenerative disease (Alzheimer's disease) ```

Answer 8

``` Age (young & elderly) Family History Head Injury Stroke & Other vascular diseases Dementia Brain Infections Seizures in Childhood ```

Answer 9

Common - 1% of population | Occurs in children and elderly

Answer 10

Partial Seizure Presentation: Frontal Lobe Focal Motor Seizure: Motor convulsions, post-ictal flaccid weakness (Todd's paralysis), Jacksonian March (spasm spreading from mouth/digit to ipsilateral side of face) Temporal Lobe Seizures: Aura (visceral or psychic symptoms), Hallucinations (usually olfactory or affecting taste) Frontal Lobe Complex Partial Seizure: Loss of consciousness, Involuntary actions/disinhibition, Rapid recovery Generalised Seizures: Tonic - sudden muscle stiffness, patient falls backwards Atonic - sudden relaxation of muscles, patient falls forwards Tonic-Clonic (Grand Mal): Vague symptoms before attack (e.g. irritability), Tonic phase (generalised muscle spasm), Clonic phase (repetitive synchronous jerks), Faecal/urinary incontinence, Tongue biting, Post-ictal phase: impaired consciousness, lethargy, confusion, headache, back pain, stiffness Absence (Petit Mal): Onset in CHILDHOOD, Loss of consciousness but MAINTAINED POSTURE, patient appears stop talking, stares into space, NO post-ictal phase Non-Convulsive Status Epilepticus: Acute confused state, often fluctuating, Difficult to distinguish from dementia

Answer 11

Tongue biting marks | Patients normal in between seizures

Answer 12

Bloods: FBC, U&E, LFT’s, Glucose, Calcium, Magnesium, ABG, Toxicology Screen, Prolactin (shows a transient increase shortly after ‘true’ seizure) EEG: helps to confirm diagnosis & classify the epilepsy 3Hz waves - absence Ictal EEGs are particularly useful CT/ MRI shows structure, space occupying or vascular lesions Other investigations: if suspected to be a secondary seizure i.e. due to infection – LP, HIV serology

Answer 13

STATUS EPILEPTICUS MX: Seizure lasting >5 minutes of continuous seizure activity or repetitive seizures without regaining consciousness ABC approach: resuscitate & protect airway, breathing and circulation Check GLUCOSE (give glucose if hypoglycaemic) and consider thiamine FIRST LINE = IV lorazepam OR IV/PR diazepam (benzodiazepine) REPEAT again after 10 minutes if seizure doesn’t stop If no response - IV phenytoin If this also fails, consider general anaesthesia (e.g. thiopentone) – intubation and mechanical ventilation required Treat the CAUSE (e.g. hypoglycaemia or hyponatraemia) Check plasma levels of anticonvulsants (status epilepticus is often caused by lack of compliance with anti-epileptic medications) Treatment of newly diagnosed epilepsy: Start anti-convulsant treatment after > 2 unprovoked seizures FOCAL Seizure 1st Line: lamotrigine or carbamazepine GENERALISED Seizure 1st Line: sodium valproate Absence = ethosuximide Other anti-convulsant: phenytoin, levetiracetam, clobazam, topiramate, gabapentin, vigabatrin Patient Education: Avoid triggers (lack of sleep, stress, alcohol, changes in medication) Use seizure diaries Consideration for women of child-bearing age as AED’s can have teratogenic effects Surgery may be considered for refractory epilepsy

Answer 14

Fractures from tonic-clonic seizures Behavioural problems Sudden death in epilepsy Complications of anti-epileptic drugs: Gingival hypertrophy (phenytoin) Neutropoenia and osteoporosis (carbamazepine) Stevens-Johnson syndrome (lamotrigine)

Answer 15

50% Remission after 1 year | Mortality: 2 in 100,000/year directly related to seizure or secondary to injury

Answer 16

An autosomal dominant condition affecting neural crest cells, resulting in multiple neurocutaneous tumours. Neurofibromatosis type I - manifests with cafe-au-lait spots, painless cutaneous nodules, Lisch iris nodules, scoliosis, optic nerve gliomas Neurofibromatosis type II - characterized by bilateral acoustic neuromas, bilateral juvenile cataracts and meningiomas

Answer 17

Autosomal dominant condition causing defiency in tumour suppressor gene Type I: Mutation in NF1 gene of chromosome 17 Type II: Mutation in NF2 gene of chromosome 22

Answer 18

Neurofibromatosis type I is more common | No gender or race predilection

Answer 19

``` Type I: Multiple painless, mobile lumps under the skin (neurofibromas) Patches of milk-coffee coloured skin on back, buttocks and thigh Pain - peripheral nerve neurofibromas Learning difficulties Headache Visual changes - optic glioma Precocious puberty ``` ``` Type II: Acoustic neuroma: Dizziness Bilateral tinnitus Bilateral gradual hearing loss ``` Catarcts: Blurring of vision Facial pain and Numbness

Answer 20

Type I: 5 Cafe-au-lait spots >15mm diameter (>5mm in children) Multiple small nodules under the skin (neurofibromas) Lisch nodules - tan bumps on iris Scoliosis Freckling in armpit or groin Type II: Decreased sensorineural hearing Catarcts Facial nerve palsy/cerebellar signs (if schwannoma is large)

Answer 21

MRI brain and spinal cord: for vestibular schwannomas, meningiomas and nerve root neurofibromas PET: may demonstrate features compatible with optic pathway gliomas, other brain tumours, hydrocephalus, paraspinal neurofibromas, MPNST Biopsy: histological features of a neurofibroma or MPNST (malignant peripheral nerve sheath tumour) Genetic testing to confirm NF1 mutation Ophthalmological assessment Audiometry Skull X-ray (sphenoid dysplasia in NF1)

Answer 22

Intracranial bleeding below the dura mater with slow bleeding, often following head trauma ACUTE: < 72 hrs SUBACUTE: 3- 20 days CHRONIC: > 3 weeks

Answer 23

Rupture of branching veins in subdural space Trauma due to rapid acceleration and deceleration of the brain Rare: rupture of cerebral aneurysm OR vascular malformation ``` Risk factors: Elderly due to brain atrophy Children due to thin walled veins Alcohol abuse Trauma Anticoagulants ```

Answer 24

More common than extradural haemorrhage Acute cases = younger patients Chronic cases = elderly

Answer 25

``` Usually delayed symptom onset due to low pressure veins Constant headache Trauma Vomiting Focal neurological symptoms Loss of consciousness Dementia-like symptoms ``` Acute: History of TRAUMA with head injury AND reduced conscious level Subacute: Worsening headache 7-14 days after injury AND Altered mental state Chronic: Headache, Confusion, Cognitive impairment, Psychiatric symptoms, Gait deterioration, Focal weakness, Seizures

Answer 26

Acute: Reduced GCS Ipsilateral fixed dilated pupil (if a large haematoma causes a midline shift) Pressure on brainstem - reduced consciousness + bradycardia Chronic: Neurological examination may be NORMAL Focal neurological signs (e.g. 3rd nerve palsy) ``` Cushing's signs of raised ICP: Bradycardia Hypotension Irregular respiration Papilloedema ```

Answer 27

CT head: Crescent shaped hyperdensity that crosses suture lines Hyperdensity = acute Hypodensity or isodensity = chronic Midline shift and ventricular compression when chronic MRI scan: Subdural fluid collection. Higher sensitivity than CT especially for isodense or smaller subdural haematomas. Plain skull x-ray: Not specific or sensitive for intracranial haematomas. Useful to identify possible skull fracture or presence of intracranial shrapnel.

Answer 28

ACUTE: Advanced life support (ALS) protocol - cervical spine control & ABC If signs of raised ICP: head elevation, osmotic diuresis (mannitol) and/or hyperventilation Children: Younger children may be treated with percutaneous aspiration via an open fontanelle Small (<10mm), no neurological signs, minimal midline shift (<5mm)- observation Large and neurological signs - decompression surgery eg craniotomy

Answer 29

``` Raised ICP Cerebral oedema Herniation Coma Stroke Neurological deficit Epilepsy ``` ``` Post-Operation: Seizures (relatively common) Subdural haemorrhage Recurrence (up to 33%) Intracerebral haemorrhage Brain abscess Meningitis Tension pneumocephalus ```

Answer 30

Acute: Underlying brain injury will affect function Chronic: Better outcome than acute subdural haemorrhages Reflects Lower incidence of underlying brain injury Good outcomes in 75% of those treated with surgery

Answer 31

Bleeding between the skull and external dura mater

Answer 32

Trauma resulting in fracture of the temporal bone, resulting in rupture to the middle meningeal artery Rarely: spontaneous Risk factors: - Bleeding tendency i.e. haemophilia or anticoagulant therapy (warfarin)

Answer 33

Common in adolescents and young adults following trauma, falls, assaults, RTAs 10% of severe head injuries

Answer 34

``` Loss of consciousness Period of lucency - asymptomatic Headache Vomiting Lethargy Neurological deficits Progressive deterioration in conscious level ```

Answer 35

``` Hypertension Wide pulse pressure Bradycardia Irregular respirations Scalp trauma or fracture to temporoparietal aspect of skull Headache Deteriorating GCS Signs of raised ICP i.e. dilated, unresponsive pupil on side of injury ```

Answer 36

Head CT: | Biconvex hyperdensity which does not cross suture lines, fracture, midline shift

Answer 37

Injury to the spinal cord with neurological symptoms depending on the site and extent of the injury and is a medical emergency

Answer 38

Spinal trauma - RTA, gunshot or knife wound, falls Vertebral fracture - low energy fracture due to weakened bone Disc herniation Tumour - primary or metastatic Infection - TB, discitis, epidural abscess ``` Cauda Equina: Lumbar disc herniation most common Spinal stenosis - congenital, ankylosing spondylitis Spondylolisthesis Tumour, cyst, abscess in spinal canal ``` ``` Risk factors: Trauma Tumour Osteoporosis Metabolic Bone Disease Vertebral Disc Disease High Risk Occupation - construction workers, bricklayers High Risk Recreational Activities - vehicle racing, horse-riding IV Drug Use Immunosuppression ```

Answer 39

``` Most common cause is trauma COMMON Trauma most common 16-30 Malignancy most common 40-75 Disc disease most common 30-50 Cauda equina: male aged 40-60 years ```

Answer 40

``` Spinal cord compression: Back pain Weakness Spastic paralysis Numbness or parasthesia Bladder or bowel incontinence Decreased anal sphincter tone Hyper-reflexia Sensory loss at lesion Priapism ``` ``` Cauda equina syndrome: Saddle anaesthesia Weakness Flaccid paralysis Bladder and bowel incontinence Reduced or absent reflexes Decreased sexual function Back pain Sciatic pain Paraplegia ```

Answer 41

Radiology - Lateral radiographs of spine to look for loss of alignment, fractures MRI or CT ``` FBC - raised WBC if infectious cause U&Es Calcium - bone mets ESR - raised if infectious cause Immunoglobulin electrophoresis (multiple myeloma) ``` Urinalysis - look for Bence Jones proteins (multiple myeloma)

Answer 42

Inflammation of the leptomeninges (pia and arachnoid mater) most commonly caused by infection, resulting in a triad of headache, fever and nuchal rigidity.

Answer 43

``` Bacterial: Neonates: Group B strep - long labour, infection in previous pregnancy E. coli - late neonatal infection Listeria monocytogenes ``` Children and teens: Neisseria meningitides Haemophilus influenzae - unvaccinated Streptococcus pneumoniae Elderly: Streptococcus pneumoniae Listeria monocytogenes - unpasteurised cheese/milk Viral: coxsackie, enterovirus, HIV, HSV Fungal: cryptococcus in immunocompromised eg HIV patients ``` Risk factors: Close communities (e.g. college halls) Basal skull fractures Mastoiditis Sinusitis Inner ear infections Alcoholism Immunodeficiency Splenectomy Sickle cell anaemia CSF shunts ```

Answer 44

Common in extremes of age

Answer 45

``` Headache Fever Photophobia Phonophobia Neck pain/stiffness Non-blanching rash - only if caused by neisseria meningitides Vomiting ``` ``` Infants: Lethargy Irritability Poor feeding Hypothermia High pitched crying ``` Confusion, mental state changes, change in consciousness, seizures if develops to meningoencephalitis

Answer 46

Kernig's sign - lie flat, lift leg and flex knee to 90 degrees, passive straightening of the leg causes back pain Brudzinski's sign - lie flat, passive flexion of the neck causes hips or knees to flex Fever Photophobia Neck stiffness Tachycardia Hypotension Buldging fontanelle in infants

Answer 47

Blood culture - 2 sets FBC - leukocytosis, anaemia CRP - elevated CT head to exclude raised ICP before LP Lumbar puncture and CSF collection: CSF glucose - decreased in bacterial and fungal CSF protein - increased in all causes, largest increase in bacterial CSF WBC - heavily elevated in bacterial with neutrophils, elevated with lymphocytes in viral and fungal CSF PCR CSF bacterial gram stain and culture

Answer 48

IMMEDIATE IV Antibiotics (before LP) First choice: 3rd generation cephalosporin - cefotaxime or ceftriaxone Empiric for neonates - cefotaxime and ampicillin Empiric teens - ceftriaxone, ampicillin, vancomycin Benzylpenicillin may be used as an initial blind therapy Dexamethasone IV - shortly before or with the first dose of antibiotics (reduces risk of complications)

Answer 49

``` Septicaemia Shock DIC Renal failure Seizures Peripheral gangrene Elevated ICP Hearing loss Brain abscess Cerebral oedema Cranial nerve lesions Cerebral venous thrombosis Hydrocephalus Waterhouse-Friderichsen Syndrome (bilateral adrenal haemorrhage caused by severe meningococcal infection) ```

Answer 50

Mortality rate from bacterial meningitis: 10-40% with meningococcal sepsis Viral meningitis is self-limiting With prompt appropriate antimicrobial and supportive therapy good outcome 15% of children develop severe sequelae

Answer 51

Pressure inside the cranium exceeding 15mmHg, due to an increase in contents of the cranium due to the fixed volume

Answer 52

``` Primary or metastatic tumours Head injury Haemorrhage - subdural, extradural, subarachnoid Infection - meningitis, encephalitis, brain abscess Hydrocephalus Cerebral oedema Status epilepticus Idiopathic intracranial hypertension ```

Answer 53

Idiopathic intracranial hypertension mainly in overweight women on childbearing age

Answer 54

Headache - worse in morning, on lying down, on coughing, straining, sneezing etc Nausea and vomiting Visual change - bilateral loss of vision momentarily on bending down, loss of peripheral fields Seizures Coma Irritability Drowsiness

Answer 55

Hypertension Bradycardia Cheyne-Stokes abnormal breathing - fast, deep breathing followed by period of apnoea Decreased GCS - coma, irritability, seizures, drowsiness Pupil constriction followed by dilation

Answer 56

FBC - infection Glucose Blood cultures - check for systemic infection Toxicology screen - cause of decreased GCS CXR - look for source of infection CT head - may see haemorrhage, tumour, abscess, hydrocephalus etc LP if no evidence of space occupying lesion