General neurological Flashcards
Where is the lesion if the pattern is affecting muscle groups, not individual muscles, with little muscle wasting, spasticity in large muscles and hyperreflexia?
UMN lesion
Where is the lesion if the pattern is affecting muscle groups, not individual muscles, with little muscle wasting, and loss of skilled fine finger movements.
UMN lesion
Where is the lesion if the affected muscles show wasting and fasciculation, there is hypotonia and hyporeflexia?
LMN lesion.
Where is the lesion if the pattern is weakness of all movements of a hand or foot, with normal or decreased tone?
Cortical lesion
Where is the lesion if there is hemiparesis with epilepsy?
Contralateral cerebral hemisphere
Where is the lesion if there is hemiparesis with decreased cognition?
Contralateral cerebral hemisphere
Where is the lesion if there is hemiparesis with homonymous hemianopia?
Contralateral cerebral hemisphere
Where is the lesion if there is hemiparesis with a contralateral cranial nerve palsy?
The brainstem on the side of the cranial nerve palsy.
Peripheral neuropathy that often causes proximal lesions
Guillain-Barre syndrome.
What lesion gives dorsal column loss on the side of the lesion, and spinothalamic loss on the contralateral side?
Brown-Sequard picture; a hemicord lesion.
What domain does carotid artery occlusion affect?
At worst, the anterior 2/3 of its hemisphere and the basal ganglia, more often it appears like a middle cerebral artery occlusive picture.
Occlusion of which artery in the brain gives just dizziness?
Superior cerebellar artery
Occlusion of which artery in the brain gives dizziness and deafness?
Anterior inferior cerebellar artery
Occlusion of which artery in the brain gives dizziness with dysphagia and dysphonia?
Posterior inferior cerebellar artery
Occlusion of which artery in the brain gives a weak numb contralateral leg and similar but milder arm symptoms, with face being spared.
Anterior cerebral artery
Occlusion of which artery in the brain gives akinetic mutism?
Bilateral occlusion of anterior cerebral arteries.
Occlusion of which artery in the brain gives hemiparesis, hemisensory loss and dysphagia?
Contralateral middle cerebral artery (of dominant hemisphere)
Occlusion of which artery in the brain gives hemiparesis, hemisensory loss and homonymous hemianopia?
Contralateral middle cerebral artery
Occlusion of which artery in the brain gives hemiparesis, hemisensory loss and visuo-spatial disturbance (can’t get dressed, gets lost etc)?
Contralateral middle cerebral artery (of non-dominant hemisphere)
Occlusion of which artery gives homonymous hemianopia only?
Posterior cerebral artery.
Drugs enhancing GABA activity are used in which conditions? What is an example of such a drug?
Epilepsy, neuropathic pain and spasticity.
Gabapentin, valproate and baclofen.
Causes of vertigo
Benign positional vertigo Acute labyrinthitis Meniere's disease Ototoxicity Acoustic neuroma Traumatic damage Herpes Zoster
What is benign positional vertigo?
Vertigo caused by debris in the semicircular canal.
Maneuvers to be used in benign positional vertigo.
Hallpike’s for diagnosis
Epley’s for treatment.
Acute labyrinthitis - symptoms
Acute vertigo, vomiting, nausea but NO tinnitus or deafness.
Meniere’s disease
Endolymphatic hydrops causes recurrent vertigo lasting more than 20 mins, sensineuronal hearing loss and tinnitus.
Meniere’s disease treatment
Antihistamine can be useful.
Surgery in very severe cases
Ototoxicity symptoms
Deafness and vertigo
Drugs with ototoxicity
Aminoglycosides, loop diuretics or cisplatin
Acoustic neuroma symptoms
A schwannoma arision from vestibular nerve.
Presents with unilateral hearing loss, with vertigo later. Ipsilateral Vth, VIth, IXth and Xth nerves may also be affected.
What must you rule out in cases of unilateral tinnitus?
Acoustic neuroma
Organic causes of tinnitus
Focal hyper-excitability in auditory cortex, hearing loss, wax, viral, presbycusis, excess noise, head injury, septic otitis media, post-stapedectomy, Meniere’s, anaemia, increased BP.
Drugs causing tinnitus
Aspirin (reversible), aminoglycosides and loop diuretics.
Where is the likely cause of a lesion causing weak legs?
Cord or distal lesion (unless parasagittal meningioma)
Causes of unilateral foot drop
DM
common peroneal nerve palsy, stroke, prolapsed disc, MS.
Causes of weak legs with no sensory loss
MND, polio, parasagittal meningioma,
Causes of chronic spastic paraparesis in the legs
MS, cord tumour, cord metastases, MND, syringomyelia, subacute combined degeneration of the cord, hereditary spastic paraparesis.
Causes of absent knee jerks and extensor plantars with leg weaknes
Combined cervical and lumbar disc disease
Conus medullaris lesions
MAST (MND or Friedreich’s ataxia, subacute degeneration of the cord, taboparesis)
What is the significance of sudden onset bilateral leg weakness?
This is an emergency; cord compression.
Can lead to permanent paralysis, faecal incontinence and neurogenic bladder.
Significance of sensory loss with leg weakness?
Spinal cord disease.
Symptoms of cord compression
Leg weakness and sensory loss
Sometimes preceded by spinal pain
Bladder and sphincter involvement manifests as hesitancy, frequency and later painless retention.
Causes of cord compression
Secondary malignancy is commonest
Rarerly: infection, cervical disc prolapse, haematoma, intrinsic cord tumour, atlanto-axial subluxation, myeloma.
Differential diagnoses for bilateral leg weakness that you think is cord compression.
Transverse myelitis, MS, carcinomatous meningitis, cord vasculitis, spinal artery thrombosis, trauma, dissecting aneurysm.
What is different about cauda equina and conus medullaris lesions compared to higher in the cord?
Leg weakness is flaccid and areflexic in the former, the reverse in the latter.
What is the cause of a rest tremor?
Parkinsonism (abolished on movement)
Cause of intention tremor?
Cerebellar damage (MS, stroke)
Causes of postural tremor?
Benign essential tremor (autosomal dominant), thyrotoxicosis, anxiety and B-agonists. Present on maintained posture.
What is chorea?
Non-rhythmic, jerky, purposeless movements flitting from place to place.
Causes of chorea?
Huntington’s disease, Sydenham’s chorea.
What is hemiballismus?
Large, flinging hemichorea contralateral to vascular lesoin of subthalamic nucleus esp in elderly diabetics.
What is athetosis?
Slow, sinuous, confluent, purposeless movements
Causes of athetosis
Cerebral palsy.
Features of MND
Rarely presents before 40
Commonly shows: fasciculation
lower motor neuron signs in arms and upper motor neuron signs in legs
wasting of the small hand muscles/tibialis anterior is common
abdominal reflexes are usually preserved and sphincter dysfunction if present is a late feature
doesn’t affect external ocular muscles
no cerebellar signs
absence of sensory signs/symptoms*
Otosclerosis
Autosomal dominant, replacement of normal bone by vascular spongy bone. Onset is usually at 20-40 years - features include:
conductive deafness
tinnitus
tympanic membrane - 10% of patients may have a ‘flamingo tinge’, caused by hyperaemia
positive family history
Typical features of a Parkinsonian tremor
Difficulty in initiating movement (bradykinesia), postural instability and unilateral symptoms (initially) are typical of Parkinson’s
Features of essential tremor
postural tremor: worse if arms outstretched
improved by alcohol and rest
most common cause of titubation (head tremor)
Management of essential tremor
propranolol is first-line
primidone is sometimes used
What is the ABCD2 score?
A scoring system for stroke. You score A Age >= 60 years B Blood pressure >= 140/90 mmHg C Clinical features - Unilateral weakness - Speech disturbance, no weakness D Duration of symptoms - > 60 minutes - 10-59 minutes Patient has diabetes
Carpal tunnel syndrome - key features of history
pain/pins and needles in thumb, index, middle finger
unusually the symptoms may ‘ascend’ proximally
patient shakes his hand to obtain relief, classically at night
Carpal tunnel syndrome - key features on examination
weakness of thumb abduction (abductor pollicis brevis)
wasting of thenar eminence (NOT hypothenar)
Tinel’s sign: tapping causes paraesthesia
Phalen’s sign: flexion of wrist causes symptoms
Guillain-Barre syndrome
An immune mediated demyelination of the peripheral nervous system often triggered by an infection (classically Campylobacter jejuni).
Guillain-Barre presentation
Progressive weakness of all four limbs. The weakness is classically ascending i.e. the lower extremities are affected first, however it tends to affect proximal muscles earlier than the distal ones. Sensory symptoms tend to be mild (e.g. distal paraesthesia) with very few sensory signs. Some patients experience back pain in the initial stages of the illness
Guillain-Barre non-presenting symptoms
areflexia
cranial nerve involvement e.g. diplopia
autonomic involvement: e.g. urinary retention
