Neurology Flashcards
What are the causes of Parkinsonism?
- Idiopathic (Parkinson’s disease) most common
- Parkinson Plus Syndromes e.g. PSP, MSA, CBD, DLB
- Basal ganglia disorders e.g. tumours, Wilson’s disease
- Normal pressure hydrocephalus
- Dementia Pugilistica (chronic head injury)
- Drugs e.g. chlorpromazine, metoclopramide, prochlorperazine
Charcot-Marie-Tooth Disease
What are the causes of pes cavus?
>BILATERAL -Charcot-Marie-Tooth disease -Friedrich's ataxia -Muscular dystrophies -Spinal muscular atrophy -Spinal cord tumours -Syringomyelia -Hereditary spastic paraparesis -Cerebral palsy >UNILATERAL -Polomyelitis, Malunion of calcaneal/talar fractures
Cerebellar Syndrome
What are the causes of bilateral cerebellar signs?
> Mnemonic: MAPLE
- MS
- Alcohol, Arnold-Chiari malformation
- Phenytoin
- Large space occupying lesion
- Endocrine (hypothyroidism)
Myotonic Dystrophy
Name the trinucleotide repeat expansion disorders.
- Myotonic dystrophy
- Huntington’s disease
- Friedrich’s ataxia
- Fragile X syndrome
- Spinocerebellar ataxia
Myotonic dystrophy
What myopathies cause distal wasting and weakness?
- Myotonic dystrophy
- Inclusion body myositis
- Oculopharyngodistal myopathy
- Welander distal myopathy
- Finish distal myopathy
- Markesbury distal myopathy
- Miyoshi myopathy
- Hereditary Motor & Sensory Neuropathy
- Distal spinal muscular atrophy
What are the causes of Peripheral Neuropathy?
> Mnemonic DAM IT BITCH:
- Drugs
- Alcohol
- Metabolic (diabetes, uraemia)
- Idiopathic & Infiltrative (amyloidosis)
- Toxins (botulism)
- B12 deficiency
- Infection (HIV, leprosy) & Post-Infectious (GBS)
- Tumour (paraneoplastic)
- Connective tissue & Congenital
- Hypothyroidism
What drugs can cause Peripheral Neuropathy?
>Motor: -Dapsone >Sensory: Antimicrobials -Metronidazole -Isoniazide -Pyridoxine -Chloroquine >Sensorimotor: Chemotherapy -Vincristine -Vinblastine -Cisplatin
Peripheral Neuropathy
What conditions can cause thickening of peripheral nerves?
- Leprosy
- Amyloidosis
- Charcot-Marie-Tooth disease
- Acromegaly
- Neurofibromatosis
Friedrich’s Ataxia
What are the causes of an absent ankle jerks with extensor plantar response?
- Friedrich’s ataxia
- Motor neurone disease
- Subacute combined degeneration of the cord (B12 deficiency)
- Tabes dorsalis
- Conus medullaris lesion
- Combination of conditions e.g. peripheral neuropathy & stroke or peripheral neuropathy & cervical myelopathy
What are the differential diagnoses of Multiple sclerosis?
- Neuromyelitis Optica (Devic’s disease)
- Acute Disseminated Encephalomyelitis
- Progressive Multifocal Leukoencephalopathy
- Paraneoplastic Encephalomyelitis
- Isolated Optic Neuritis
What are the different types of Nystagmus?
- Cerebellar Nystagmus: Coarse horizontal nystagmus, Fast component towards side of lesion.
- Peripheral Vestibular Nystagmus: Horizontal nystagmus, Fast component away from side of lesion
- Central Vestibular Nystagmus:Horizontal/Vertical/Rotatory/Mixed. Can be bidirectional.
- Ataxia Nystagmus: INO
- Pendular Nystagmus: Blindness/Congenital
- Downbeat Nystagmus: Lesion at Foramen magnum.
- Upbeat Nystagmus: Cerebellum or Medulla
Ophthalmoplegia
What are the features of a VI Nerve Palsy?
What are the causes of a VI Nerve Palsy?
> Features:
-Convergent strabismus at rest
-Impaired abduction of affected side
Causes:
-Raised intracranial pressure
-Cavernous sinus lesions (tumour, infection, thrombosis, aneurysm)
-Vascular (infarct, haemorrhage, basilar artery aneurysm)
-Inflammation (multiple sclerosis, sarcoidosis)
-Infection (syphilis)
-Mononeuritis Multiplex
Ophthalmoplegia
What are the features of a III Nerve Palsy?
What are the causes of a III Nerve Palsy?
>Features: -Divergent strabismus -Pupil down & out -Pupil fixed & dilated >Causes: -Posterior communicating artery aneurysm -Cavernous sinus lesions -Vascular -Inflammation -Infection -Mononeuritis Multiplex
Ophthalmoplegia
What are the features of a IV Nerve Palsy?
What are the causes of a IV Nerve Palsy?
>Features: -Affected eye higher than normal eye in primary gaze -Adduced eye cannot look down -Characteristic head tilt away from affected side >Causes: -Trauma -Cavernous sinus lesion -Mononeuritis Multiplex -Brainstem lesion
Ophthalmoplegia
What are the structures in the cavernous sinus?
What are the causes of a cavernous sinus syndrome?
> Structures:
-Cranial nerves III, IV, VI, Va/Vb
-Sympathetic carotid plexus
-Intracavernous carotid artery
Causes:
-Tumour (meningioma, neurofibroma, nasopharyngeal)
-Trauma
-Thrombosis
-Infection & Inflammation (HZA, TB, Sarcoidosis, GPA)
-Aneurysm (Intracavernous carotid artery, PCOM artery)
What are the differential diagnoses for Myasthenia Gravis?
- Botulism
- Lambert Eaton Myasthenic Syndrome
- Mitochondrial myopathy
- Miller-Fisher Syndrome
- Snake bites
- Avoid Aminoglycosides, Phenytoin, Antimuscarinic agents
Where is the lesion in the following visual field defects:
bitemporal hemianopia, homonymous hemianopia, homonymous upper quadrantanopia, homonymous lower quadrantanopia?
- Bitemporal hemianopia: Optic chiasm.DDx include pituitary tumour, craniopharyngioma, suprasellar meningioma.
- Homonymous hemianopia: Optic tract or radiation.
- Homonymous upper quadrantanopia: Temporal cortex.
- Homonymous lower quadrantanopia: Parietal cortex.
DDx include cerebrovascular accident, intracranial tumour, trauma.
What are the differential diagnoses of wasting of small muscles of the hands?
> Anterior Horn Cells at C8-T1:
-Motor neurone disease, Syringomyelia, Cervical Cord tumour, Distal spinal muscular atrophy, HMSN, Friedrich’s ataxia, Old poliomyelitis, Polyneuropathy
Nerve Root at C8-T1:
-Pancoast tumour, Neurofibroma, Cervical myelopathy
Lower Brachial Plexus:
-Pancoast tumour, Cervical myelopathy
Muscle Disorders:
-Myotonic dystrophy, Distal muscular dystrophies
Trophic: Disuse, Complex pain syndrome
What are the clinical features of syringomyelia?
What are other causes of dissociated sensory loss?
> Clinical Features of Syringomyelia:
-Distal wasting & weakness, Prominent wasting of small muscles of the hands
-LMN signs in upper limbs, UMN signs in lower limbs
-Trophic & vasomotor changes (painless scars, ulcers, digital amputations)
-Sensory involvement in cape like distribution with dissociated sensory loss (affected pain/temperature, preserved vibration/proprioception)
Causes of Dissociated Sensory Loss:
-Syringomyelia, Anterior Spinal Artery Occlusion, Small Fibre Neuropathies
What are the features of ulnar nerve palsy?
> Features of Ulnar Nerve Palsy:
- Wasting of 1st dorsal interossei & adductor digiti minimi-Weakness of finger adduction & abduction
- Weakness of flexion of 4th/5th DIP joints (if proximal)
- Claw hand if distal lesion
- Froment’s Sign (affected thumb flexes on gripping piece of paper between lateral half of index finger)
- Sensory loss in ulnar distribution
What are the features of radial nerve palsy?
> Features of Radial Nerve Palsy:
- Wrist drop (weakness of wrist & finger extension)
- Sensory loss over 1st dorsal interossei
- Weak forearm supination & elbow extension & impaired triceps jerk with sensory loss over posterior forearm & triceps if proximal lesion
What are the features of median nerve palsy?
> Features of Median Nerve Palsy:
- Wasting of abductor pollicis brevis
- Weakness of thumb abduction
- Weakness of flexion of 1st/2nd DIP joints if proximal
- Numbness in median nerve distribution
- Tinel’s, Phalen’s positive if carpal tunnel compression
What are the features of a relative afferent pupillary defect (RAPD)?
What are the causes of a RAPD?
> Features:
-Direct & Consensual reflexes intact. During swinging torch test affected pupil dilates.
Causes:
-Optic nerve disorders e.g. optic neuritis
-Retinal disorders e.g. central retinal vein occlusion, central retinal artery occlusion, severe ischaemic diabetic retinopathy, retinal detachment
What are the features of an Argyll-Robertson pupils?
What are the causes of an Argyll-Robertson pupils?
> Features:
-Mnemonic Like a Prostitute (accommodate but do not react), Occurs in Prostitutes
-Both pupils are small & irregular
-They react to accommodation but not to light
Causes:
-Neurosyphilis (most common)
-Diabetes
-Lyme disease, Wernicke’s encephalopathy
-Brainstem encephalitis
-Midbrain lesions e.g. tumour, infarct, haemorrhage, demyelination, syringobulbia, sarcoidosis
What is the Holmes-Adie Syndrome?
- Idiopathic benign disorder in middle aged females
- Adie tonic pupil (unilateral dilated pupil that reacts slowly to light & accommodation) with Absent deep tendon reflexes +/- Autonomic disturbances
Horner’s Syndrome
What are the causes of Horner’s Syndrome?
> 1st. Central: Anhidrosis of face, arm, upper trunk
-Demyelination, Brainstem or Spinal cord tumour/haemorrhage/infarction, Syringomyelia, Arnold-Chiari malformation
> 2nd. Peripheral (preganglionic): Anhidrosis of face only
-Pancoast tumour, Cervical rib, Central venous catheterization, Neck surgery
> 3rd. Peripheral (postganglionic): No anhidrosis
-Internal carotid artery dissection, Carotico-cavernous fistula, Herpes Zoster*Common causes incl. Apical lung cancer, Neck cancer, Cartodi artery aneurysm, Syringomyelia, etc.
Horner’s Syndrome
What are the causes of bilateral ptosis?
- Myaesthenia
- Myopathies e.g. myotonic dystrophy, chronic progressive external ophthalmoplegia, oculopharyngeal muscular dystrophy
- Bilateral Horner’s Syndrome e.g. syringomyelia
- Tabes dorsalis
Cerebellopontine Angle Lesion
What structures are affected?
What are the causes of a cerebellopontine angle lesion?
>Structures Affected: -Multiple cranial neuropathies (CN V, VI, VII, VIII). >Causes: -Acoustic neuromas most common cause -Meningiomas second most common cause -Nasopharyngeal carcinoma -Medulloblastoma -Cholesteatoma -Haemangioblastoma -Granuloma -Basilar artery aneurysm -Metastases
Bulbar & Pseudobulbar Palsy
What are the causes of Bulbar Palsy?
> Bulbar Palsy is caused by LMN disease:
- Motor neurone disease
- Brainstem e.g. vascular, tumour
- Poliomyelitis
- Guillain-Barre syndrome
- Myasthenia gravis
- Muscular dystrophies
Bulbar & Pseudobulbar Palsy
What are the causes of Pseudobulbar Palsy?
> Pseudobulbar palsy is caused by UMN disease:
- Bihemispheric vascular disease
- Multiple sclerosis
- Motor neurone disease
- Brainstem eg. vascular, tumour
- Trauma
Brainstem Syndrome
What is the brainstem rule of fours?
> 4 Cranial Nerves: APM
-Above Pons I-IV, Pons V-VIII, Medulla IX-XII
4 Medial Structures: 4 M’s
-Medial lemniscus - contralateral loss vibration/proprioception
-Motor pathway - Contralateral arm/leg weakness
-MLF - Ipsilateral INO
-Motor nucleus/nerve - Ipsilateral Cranial nerve loss
4 Lateral Structures: 4 S’s
-Spinothalamic - Contralateral loss pain/temperature
-Spinocerebellar - Ipsilateral Ataxia
-Sympathetic - Ipsilateral Horner’s
-Sensory Nucleus CN V - Ipsilateral facial loss pain/temp
Peroneal Nerve Lesion
What are the clinical features?
- Motor: Weak dorsiflexion & eversion. Inversion is preserved.
- Little or No Sensory loss, with anaesthesia over the lower lateral aspect of their legs and dorsa of the feet
- Risk Factors include tight plaster casts, sports injuries, diabetes
Charcot-Marie-Tooth Disease
What is the inheritance?
What are the clinical features?
AD inheritance Clinical features: -Pes cavus (short high-arched feet, hammer toes) -Distal muscle atrophy -Thickened nerves -Absent reflexes -Slight or no sensory loss
Muscular Dystrophy
What are the clinical features of Duchenne’s & Becker’s Muscular Dystrophy?
- Calf hypertrophy
- Proximal muscle weakness
- Preserved reflexes
- Dilated cardiomyopathy
- Ducenne’s is more severe
Brown Sequard Syndrome
What are the clinical features?
- Ipsilateral loss of vibration, proprioception
- Contralateral loss of pain, temperature
Friedrich’s Ataxia
What is the inheritance?
What are the clinical features?
>Inheritance: -AR-Mutation is Frataxin on Chromosome 9 >Clinical Features: -Young patient -Bilateral cerebellar signs -Loss of dorsal columns (vibration, proprioception) -Absent ankle jerks -Pes cavus -Other features incl. cardiomyopathy, diabetes, kyphoscoliosis
Facial Muscle Weakness
What are the causes of bilateral facial weakness?
>UMN causes incl. Stroke, Tumour, Demyelination >LMN known as Bell's Palsy >Bilateral Facial Weakness: -Guillain Barre Syndrome -Myopathy incl. myotonic dystrophy, fascio-scapulo-humeral dystrophy -Myasthenia Gravis -Sarcoidosis -Motor Neurone Disease
Parinaud’s Syndrome
Where is the lesion?
What are the causes?
What are the clinical features?
>Lesion: -Dorsal midbrain >Causes: -Central: MS, Pinealoma, Vascular -Peripheral: Diabetes, Trauma >Clinical Features: -Loss of upward gaze -Convergence retraction nystagmus -Pseudo Argyll Robertson Pupil
Foot DropWhat are the causes?
>Unilateral -Common peroneal nerve lesion -L5, S1 Radiculopathy -Sciatic nerve lesion -Peripheral neuropathy -Myopathy -Motor Neurone Disease >Bilateral: -Neuropathy e.g. diabetes, vasculitis -Bilateral radiculopathy -Cauda equina or conus medullaris lesion -Motor neurone disease -Spastic paraparesis
Subacute Combined Degeneration of the Spinal Cord
What are the clinical features?
- Absent dorsal column (vibration, proprioception)
- Absent ankle jerk with extensor plantar
- Ataxic gait-Others: Optic atrophy, Dementia
Obturator Nerve Lesion
What are the clinical features?
What are the risk factors?
>Clinical Features: -Weak hip/thigh adduction -Sensory changes medial aspect of thigh >Risk factors: -Labour -Pelvic malignancy
Lateral cutaneous nerve of thigh lesion
What is the name?
What are the clinical features?
What are the risk factors?
>Name: -Meralgia paraesthetica >Clinical Features: -Paraesthetsia anterolateral aspect of thigh>Risk Factors: -Pregnancy -Obesity -Rapid weight loss
Femoral Nerve Lesion
What are the clinical features?
What are the risk factors?
> Clinical Features
- Weak thigh flexion
- Absent knee reflex
- Sensory loss anteromedial thigh
- Wasting of quadriceps>Risk Factors:
- Diabetes
- Retroperitoneal haematoma
- Pelvic malignancy
- Femoral hernia
- Femoral aneurysm
Cervical Rib Syndrome
What are the clinical features?
> Clinical Features:
- Wasting & weakness of small muscles of the hand
- Sensory loss on medial hand & forearm
- Unequal radial pulses & blood pressure
- Subclavian bruit
- Palpable cervical rib
Myopathy
What are the differential diagnoses for myopathy?
>Mnemonic: PACE PODS for Acquired -Hereditary -Acquired includes: Polymyositis, Dermatomyositis Alcohol Carcinoma Endocrine (hypothyroidism, hyperthyroidism, Cushing's syndrome, hypopituitarism) Periodic paralysis Osteomalacia Drugs e.g. steroids Sarcoidosis
Charcot-Marie-Tooth Disease
What are the differential diagnoses?
>Hereditary: -Hereditary neuropathy with liability to pressure palsy -Hereditary neuralgic amyoptrophy -Friedrich's ataxia -Spinal muscular atrophy >Acquired: -CIDP -Peripheral neuropathy e.g. alcohol, diabetes, vasculitis, amyloid, heavy metal poisoning
Klumpke Lower Brachial Plexus Lesion
Where is the lesion?
What are the clinical features?
> Lesion:
- C8/T1 lesion>Clinical Features:
- Claw hand
- Paralysis of intrinsic muscles of hand
- Sensory loss on ulnar side of arm/forearm
- Horner’s syndrome
Erb-Duchenne Upper Brachial Plexus Lesion
Where is the lesion?
What are the clinical features?
> Lesion:
- C5/6 lesion>Clinical Features:
- Loss of shoulder movement & elbow flexion (waiter’s tip position)
- Sensory loss over lateral aspect of arm/forearm
Motor Neurone Disease
What are the clinical features?
What does EMG demonstrate?
What is the management?
> Clinical Features:
- Bulbar or Pseudobulbar palsy
- Mixed LMN & UMN signs with spasticity, extensor plantars, fasciculations, atrophy
- Dementia, Dysphagia, Dysarthria>EMG:
- Diffuse denervation with fibrillation>Management:
- PT/OT/SP/Dietitian
- PEG feeding if Dysphagia
- NIV if respiratory failure
- Riluzole
- Antidepressants
Cranial Nerve III (Oculomotor nerve palsy)
What are the clinical features?
What are the causes?
> Clinical Features:
-Divergent strabismus
-Ptosis
-Fixed dilated pupil not reactive to light or accommodation
Causes:
- Central: Vascular, Tumour, Demyelination, Trauma
- Peripheral: PCOM aneurysm, Nasopharyngeal carcinoma, Meningitis, ORbital lesion (Tolosa Hunt syndrome)
Parkinson’s Disease
What are the clinical features?
- Gait festinating, freezing, short arm swing
- Postural instability
- Asymmetric resting tremor
- Bradykinesa, MIcrographia
- Rigidity
- Masked facies
- Hypometric saccades
- Neuropsychiatric: Dementia
Parkinson’s Disease
What are the investigations?
- CT Brain to exclude normal pressure hydrocephalus
- MRI Brain
- PET/SPECT
- Wilson’s Disease: 24-hour urine copper, Caeruloplasmin
Parkinson’s Disease
What is the management?
- Dopamine plus peripheral dopamine decarboxylase inhibitor e.g. levodopa/carbidopa, levodopa benserazide
- Monoamine oxidase inhibitor e.g. rasagiline
- Dopamine agonist e.g. pramipexole, apomorphine
- NMDA antagonists e.g. amantadine
- COMT inhibitor e.g. entecapone
- Deep Brain Stimulation*Avoid Metoclopramide
Multiple Sclerosis
What is the management?
>Acute Relapses: -Pulsed methylprednisolone -Plasma exchange >Disease Modifying Drugs: -Interferon beta-1a or beta-1b -Glatiramer acetate -Teriflunomide-Dimethyl fumarate -Fingolimod (sphingosine-1-receptor modulator) -Natalizumab (MAb to alpha-4-integrin) -Alemtuzumab (MAb to CD52)
Multiple Sclerosis
What are the clinical features?
What are the investigations?
Clinical Features: -Optic neuritis, INO -Bladder/Bowel incontinence/retention -Uhthoff phenomenon -Dysphagia, Dysarthria -Fatigue, Depression, Cognitive impairment >Investigations: -MRI Brain/Spinal Cord Gadolinium (periventricular, juxtacortical, Infratentorial, spinal cord lesions) -CSF (elevated IgG oligoclonal bands) -Visual & Auditory evoked potentials -Anti-Aquaporin 4 antibody
Movement Disorders
What are the causes of chorea?
What are the causes of Tic?
>Chorea: -Huntington's disease -Sydenhams' chorea -SLE -Polycythaemia >Tic: -Tourette's syndrome
Hereditary Spastic Paraparesis
What are the clinical features?
What are the differential diagnoses?
>Clinical Features: -Increased tone, Clonus -Increased reflexes, Crossed adductors -Weakness, Mild wasting -Scissor gait -Extensor plantar response >Differential Diagnoses: -Cord compression, tumour, abscess, ischaemia etc -Demyelination -Motor Neurone Disease -Friedrich's ataxia -Syringomyelia
Spinocerebellar Ataxia
What are the clinical features?
- Cerebellar ataxia
- UMN signs
- Sensory neuropathy
- Sometimes LMN signs
- Cognitive impairment
Multiple Cranial Nerve Palsies?
What are the causes?
>Central: -Vascular -Tumour -Demyelination -Motor Neuron Disease -Syringomyelia/Syringobulbia >Peripheral: -Nasopharyngeal carcinoma -Cerebellopontine angle lesion e.g. acoustic neuroma -Chronic meningitis -Guillain Barre Syndrome -Trauma e.g. basal skull fracture
Inclusion Body Myositis
What are the clinical features?
What are the investigations?
>Clinical Features: -Elderly male -Proximal muscle weakness -Neck flexor weakness -Quadriceps & Forearm atrophy >Investigations: -CK, Anti-CN1a -Muscle biopsy - CD8+ T-cells, Congophilic amyloid deposits, Ragged red fibres*Does not respond to immunosuppressionS
Sciatic Nerve LesionWhat are the clinical features?What are the risk factors?
Clinical Features:
-Weak knee flexion and muscles below knee, Foot drop
-Sensory loss on sole & dorsum of foot, posterior & lateral leg
>Risk Factors:
-Trauma
-Pelvic fracture
-Pelvic malignancy
