Neurology Flashcards
Causes of a unilateral high stepping gait / foot drop?
And how to differentiate?
- L5 (FIVE) nerve pathology - inversion and eversion of the ankle will also be weak (and hip abduction)
- Peroneal nerve pathology - eversion of the ankle is also weak, inversion is preserved (not hip abduction)
- Sciatic nerve pathology - inversion, eversion, dorsiflexion and plantar flexion weak, loss of achilles jerk
Plus associated sensory changes
UMNL vs LMNL
UMNL
- No fasciciulations
- Wasting a late sign from disuse atrophy
- Tone increased
- Clasp knife in pyramidal
- Lead pipe in extra-pyrmaidal
- Cogwheel in extra-pyramidal plus superimposed tremor
- Spastic paralysis
- Weakness of anti-gravity muscles in upper limbs (abductors, elbow/wrist extensors)
- Weakness of flexors in lower limbs
- Increased reflexes
- Clonus present
- Upgoing Babinksi
LMNL
- Fasciculations
- Wasting
- Tone decreased
- Clonus absent
- Downgoing Babinksi
- Flaccid paralysis
What are the causes of a +ve Rhombergs?
- Peripheral neuropathy (usually with loss of proprioception)
- Posterior column disease (tabes dorsalis)
- Vestibular neuropathy
What are the causes of a small-stepping gait?
Parkinsonian
- Stooped posture, little arm swing
Parkinsons-like
- PSP
- Drug-induced parkinsons
- NPH - gait a little more broad based
- Multiple lacunar infarcts - UMN findings in LLs
What are the features and causes of a unilateral spastic / hemiparetic gait?
Causes
- CVA
- Central lesion
Features
- UL posture: adducted, IR, elbow and wrist flexed
- LL: leg circumducts
BIlateral spastic gait or a paraparetic gait
What are the causes or features.
Causes
Spinal cord lesion
- Infarction
- Trauma
- Compression
- MS
Cerebral palsy
BIlateral CVAs
Hereditary spastic paraparesis
Features
Scissoring gait
What are the causes of a wide based gait?
What else is it associated with?
Cerebellar syndrome
Truncal ataxia
Rhomberg’s negative
What are the causes of peripheral neuropathy?
DUCE HHIIVAMM
Common
Diabetes (predominantly sensory and small fibre) / Drugs (D-drugs, amiodarone, isoniazid)
Uraemia (ESKD)
CIDP (predominantly motor or large fibre sensory)
EtOH
Less common
Hereditary
Hypothyroidism
Infection (HIV)
Vasculitis
Amyloidosis
Malignancy (chemotherapy - vincristine, cisplatinum, pacitaxel or paraneoplastic)
Multiple myeloma / Paraproteineimia / POEMS
Specifying peripheral neuropathy
Sensory-predominant
(small or large fibres)
- Motor-predominant*
- Senosory motor*
What are the results of nerve conduction studies in an axonopathy (usually sensory and small fibre)?
Reduced amplitude
Normal conduction
No conduction block
What are the results of nerve conduction studies in demyelinating neuropathy (motor or predominantly large fibre)?
Amplitude normal
Conduction velocity reduced
Conduction block may be present if acute
What are the investigations for peipheral neuropathy?
Review medication chart
Urinalysis for glucose(NOT for bence jones protein)
HbA1c
UEC
EtOH
B12
TFTs
ESR / CRP / ANCA / ANA
SPEP & serum free light chains, Hb, Calcium
Nerve conduction studies
Causes of unilateral UMN findings.
What are other features of each?
Causes of unilateral UMN findings
- Stroke (ischaemic haermorrhagic, thrombosis)
- Would expect ipsilateral sensory changes also
- See other flashcard for cortical vs subcortical
- Other central lesion
- Tumour
- Abscess
- Spinal cord lesion
- Brown Sequard - ipsilateral doral column loss and contralateral spinothalamic loss
- Multiple sclerosis
- Often bilateral
- Sensory findings variable
- May also be bilateral and have cerebellar findings
- Optic neritis, INO
- Autonomic involvement
- Cerebral palsy
- Often bilateral
- No sensory changes
- Motor neuron disease
- Often bilateral
- Should see LMN signs also
What causes bilateral UMN findings?
What are the other features of each?
Causes of bilateral UMN findings
- Multiple sclerosis
- May have sensory findings
- May have cerebellar findings
- Optic neuritis, INO
- Autonomic dysfunction
- Multiple strokes (ischaemic haermorrhagic, thrombosis)
- Often lacunar strokes
- Associated with sensory findings
- BIlateral intracranial space occupying lesion (eg tumour or abscess)
- Spinal cord lesion
- Spinal cord compression
- Arnold Chiari Malformation
- Cerebral palsy
- Without sensory findings
- Motor neuron disease
- Mis of UMN and LMN lesions
- Hereditary - CMT
What are the causes of Parkinsonism
- Idiopathic PD
- Medications (Chlorpromazine, prochlorperazine, metoclopramide, sodium valproate, methyldopa)
- Parkinson’s plus syndromes
- MSA-P
- PSP
- CBD
- Basal ganglia infarcts or space occupying lesions in this area
- NPH
What are the features of Parkinsonism
Resting tremor
Rigidity
Bradykinesia
Autonomic instability
What are the features of Parkinsons Plus (overall) and the specific syndromes?
Overall
- More symmetrical
- More rapidly progressive
- Poor response to levodopa
PSP
- Vertical saccades ophthalmoplegia (and then horizontal)
- Early falls
- Extension - falls backward
MSA-P
- Could be associated with cerebellar signs (MSA-C) or autonomic instability (MSA-A)
CBD
- Stooped forward posture
- Cognitive / behavioural disturbance
- Limb apraxia - alien hand
Causes of proximal muscle myopathy?
Distal muscle myopathy?
Proximal
Drugs: steroids, statins, EtOH
Endo: diabetes, hypothyroidism or hyperthyroidism
Inflammatory causes: PM, DM, IBM
Rare and heridtiary: mitichondrial, MD
Distal
Any of above but mainly IMB, MD
What are the cortical signs?
Face/arm weakness > leg (MCA)
Leg > face/arm (ACA)
Dominant hepisphere: dysphsia / aphsia + Gerstman’s syndrome
(Finger agnosia, agraphia, acalculia, L-R confusion)
Non-dominant: inattention, apathy, emotional changes
What are the subcortical signs?
Absence of cortical signs
Face / arm / leg equally affected
Unusual movements (basal ganglia)
What are the lacunar stroke syndromes
Pure motor
Pure sensory
Sensory motor
Ataxia & hemiparesis
Dysarthria & clumsy hand
Causes of weakness (without UMNL findings)
Spinal cord
MND (with UMN findings)
Polio: anterior horn cels
LMNL
Peripheral nerve lesion (root, trunk, division, cords, plexus)
Acquired peripheral neuropathy: CIDP, diabetes
Inherited peripheral neuropathy: eg Charcot Marie Tooth
Neuromuscular
MG
Lambert Eaton
Myopathy
Drugs: steroids, statins
EtoH, diabetes, hypothyroidism
What causes subacute combined degeneration of the spinal cord?
What is a typical presentation?
What ares of the spinal cord are affected?
SACD = Lichtheim’s disease
Caused by:
Vitamin B12 deficiency (pernicious anaemia)
Vitamin E deficiency
Copper deficiency
Nitrous oxide poisoning (used in anaesthetic agents)
Presentation:
The clinical presentation of SACD is usually with loss of vibration and proprioception in the hands and feet (DORSAL COLUMNS), with eventual progression to sensory loss of all modalities, sensory gait ataxia, and distal muscle weakness (LATERAL COLUMNS), especially of the legs.
Subacute combine degeneration of the cord vs Tabes dorsalis
Which has motor/more broad involvement?
Subacute combined degeration of the cord
- progresses to sensory loss in all modalities
- progresses to involve the motor / lateral columns of the lower limbs
Signs of cerebellar syndrome
Gait
Wide based
Truncal ataxia
Negative Rhombergs
IPSILATERAL
dysdiadochokinesis
dysmetria
intention tremor
hypotonia
Cranial nerves
horizontal nystagmus (fast component toward the side of the lesion)
broken smooth pursuit
overshooting saccades
dysarthria
Causes of cerebellar syndromes
Stroke
Posterior fossa space occupying lesions
Demyelination
Alcohol
Hypothyroidism
Drugs (Lithium, phenytoin, carbemazepine, chemo agents)
If there are crossed signs think
(cranial nerves on one side, motor/sensory on the other)
brainstem syndromes
Type of gait in proximal myopathy
waddling gait
Radial nerve pathology.
<em>Deformity?</em>
<em>Wasting?</em>
<em>Power?</em>
(Peripheral nerve power test)
<i>Reflexes?</i>
<i>Sensation?</i>
Wrist drop
Reduced power wrist and MCP joint extension (not IPJ extension)
Peripheral nerve power test is MCP extension
Wasting of triceps and forearm
Reduced elbow extension if lesion is above spiral grooice (axilla)
Reduced triceps jerk if lesion is above spiral goorive (axilla)
Reduced sensation first dorsal interosseus space
Median nerve lesion
Deformity?
Wasting?
Power?
(Peripheral nerve power test)
Reflexes?
Sensation?
Hand of benediction
Thenar msucle wasting
Thumb abduction power reduced
Opposition power reduced
3.5 fingers and thenar surface of palm
Ulnar nerve lesion
Deformity?
Wasting?
Power?
(Peripheral nerve power test)
Reflexes?
Sensation?
Claw hand
Hypothenar wasting
MCP abduction (aplying of fungers) weak
1st MCP adduction (hold paper) weak
Ulnar 2 fingers
