Pattern recognition in Neurology

Question 1

What factors are looked at when checking for Neurological patterns?

Answer 1

Type of weakness
Type of sensory symptoms
The presence or absence of autonomic or bulbar dysfunction
Time course of events is vital

Can be obtained with skilful medical history

Question 2

What areas to look for in neurological defects?

Answer 2

CNS:
- Brain: grey and white matter tracts
- Spinal cord: cross-section (tracts) and segments (cervical/thoracic/lumbar).

PNS:
- Spinal nerve, root, plexus and peripheral nerves.

Neuromuscular junction

Muscle

Question 3

Weakness in neurology can be focal or generalised. True/false?

Answer 3

True

Question 4

Difference between focal and generalised weakness?

Answer 4

Focal:
- In distribution of peripheral nerve or spinal root.
- Hemi-distribution (one side of body)
- Pyramidal distribution

Generalised (non-focal):
- Predominantly proximal or distal
- If truly generalised: including bulbar motor function otherwise quadri- or tetraparesis.

Question 5

Upper motor neuron signs in MND?

Answer 5

Increased tone (hypertonia)
Increased reflexes (hypereflexia)
Extensor plantar responses (positive babinski sign)
Spastic gait
Exaggerated jaw jerk
Slowed movements

Question 6

Lower motor neuron signs in MND?

Answer 6

Muscle wasting
Weakness
Fasciculations (brief spontaneous muscle contractions)
Absent or reduced deep tendon reflexes

Question 7

Lower motor neuron disease follows a pyramidal/corticospinal pattern of weakness. True/false?

Answer 7

False. UMN disease follows the pyramidal/corticospinal pattern of weakness.

Showing weak arm extensors and weak leg flexors.

Question 8

Muscle disease pattern of weakness?

Answer 8

Wasting (usually proximal), decreased tone, decreased or absent tendon reflexes

Question 9

Neuromuscular junction pattern of weakness?

Answer 9

Fatiguable weakness, normal or decreased tone, normal tendon reflexes. No sensory symptoms!

Question 10

Functional weakness pattern?

Answer 10

no wasting, normal tone, normal reflexes, erratic power, non-anatomical loss

Question 11

Pattern of UMN lesions in CNS?

Answer 11

Hemispheric: contralateral pyramidal weakness in face, arm, leg (homunculus!)

Parasagittal frontal lobe lesion: Paraparesis

Spinal cord: pyramidal weakness below the level of the lesion

cervical: arms and legs

Thoracolumbar: legs

Question 12

Pattern of LMN lesions in anterior horn cells?

Answer 12

Occurs with motor neuron disease, spinal muscular atrophy, (lead poisoning, poliomyelitis,…)

Time course of the illness, age of onset and family history, exposure history in addition to targeted investigations will help differentiate

Question 13

Root innervation/deep tendon reflexes?

Answer 13

S1,2 (ankle)
L3,4 (knee)
C5,6 (biceps)
C7,8 (triceps)

Question 14

UMN/pyramidal movement disorder features?

Answer 14

• Pyramidal weakness
• Spasticity

Question 15

Extrapyramidal (in basal ganglia) movement disorder features?

Answer 15

Hyperkinetic MD
- Dystonia
- Tics
- Myoclonus
- Chorea
- (Tremor)

Hypokinetic (rigidity, bradykinesia)
- Parkinsonism
- Parkinson’s disease

Question 16

Cerebellar signs/coordination

Answer 16

Cerebellar gait is broad-based and unsteady

Intention tremor / ataxia is assessed in the arms by finger-nose test and in the legs by knee-heel testing. Tremor gets exaggerated the nearer the target

Dysdiadochokinesis: clumsy fast alternating movements

Nystagmus and dysarthria are additional features of cerebellar disorders

Question 17

Temporal lobe dysfunction signs/symptoms?

Answer 17

Memory dysfunction especially episodic memory

Agnosia (visual and sensory modalities in particular)

Language disorders eceptive dysphasia (Wernicke, dominant hemisphere)

Visual field defects (congruous upper homonymous quadrantanopia)

Auditory dysfunction (Heschel’s gyrus, as hearing is represented bilaterally, deafness is not a cerebral feature)

Limbic dysfunction

Temporal lobe epilepsy

Question 18

Parietal lobe dysfunction signs/symptoms?

Answer 18

Visual field defect (congruous lower homonymous quadrantanopia)

Sensory dysfunction (visual and sensory modalities in particular)

Gerstmann’s syndrome (disease of the dominant angular gyrus, part of the inferior parietal lobe): Dysgraphia, left-right disorientation, finger agnosia, acalculia

Dyspraxia

Inattention (non-dominant angular gyrus)

Denial

Question 19

Roles of the frontal lobe?

Answer 19

Frontal lobe: generates novel strategies and has executive functions. It enables self-criticism and trying again. The prefrontal cortex connects extensively to other association cortices, basal ganglia, limbic system, thalamus and hippocampus

• Orbitofrontal cortex: response to primitive stimuli (hunger, thirst, sexual function) damage causes disinhibition
• Dorsolateral prefrontal cortex: response to external stimuli (executing work responsibilities)
• Cingulate gyrus and dorsomedial frontal lobe: motivation, damage causes abulia (lack of will) or even akinetic mutism

Question 20

Role and location of the hippocampus?

Answer 20

Embedded deep in the medial aspect of the temporal lobe of the brain. It has a major role in learning and memory.

Question 21

Role and location of the thalamus?

Answer 21

Thalamus is the body’s information relay station. All information from the body’s senses (except smell) must be processed through the thalamus. Located near the centre of the brain, just above the midbrain.

Question 22

What is treatment protocol for Parkinson’s disease?

Answer 22

Symptomatic treatment with Levodopa replacement or dopamine agonist

Multidisciplinary team management including Speech and language, OT, PT, exercise

For selected patients deep brain stimulation (subthalamic nucleus, globus pallidus int)