Pattern recognition in Neurology Flashcards
What factors are looked at when checking for Neurological patterns?
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
What areas to look for in neurological defects?
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
Weakness in neurology can be focal or generalised. True/false?
True
Difference between focal and generalised weakness?
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.
Upper motor neuron signs in MND?
Increased tone (hypertonia)
Increased reflexes (hypereflexia)
Extensor plantar responses (positive babinski sign)
Spastic gait
Exaggerated jaw jerk
Slowed movements
Lower motor neuron signs in MND?
Muscle wasting
Weakness
Fasciculations (brief spontaneous muscle contractions)
Absent or reduced deep tendon reflexes
Lower motor neuron disease follows a pyramidal/corticospinal pattern of weakness. True/false?
False. UMN disease follows the pyramidal/corticospinal pattern of weakness.
Showing weak arm extensors and weak leg flexors.
Muscle disease pattern of weakness?
Wasting (usually proximal), decreased tone, decreased or absent tendon reflexes
Neuromuscular junction pattern of weakness?
Fatiguable weakness, normal or decreased tone, normal tendon reflexes. No sensory symptoms!
Functional weakness pattern?
no wasting, normal tone, normal reflexes, erratic power, non-anatomical loss
Pattern of UMN lesions in CNS?
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
Pattern of LMN lesions in anterior horn cells?
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
Root innervation/deep tendon reflexes?
S1,2 (ankle)
L3,4 (knee)
C5,6 (biceps)
C7,8 (triceps)
UMN/pyramidal movement disorder features?
- Pyramidal weakness
- Spasticity
Extrapyramidal (in basal ganglia) movement disorder features?
Hyperkinetic MD
- Dystonia
- Tics
- Myoclonus
- Chorea
- (Tremor)
Hypokinetic (rigidity, bradykinesia)
- Parkinsonism
- Parkinson’s disease
Cerebellar signs/coordination
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
Temporal lobe dysfunction signs/symptoms?
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
Parietal lobe dysfunction signs/symptoms?
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
Roles of the frontal lobe?
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
Role and location of the hippocampus?
Embedded deep in the medial aspect of the temporal lobe of the brain. It has a major role in learning and memory.
Role and location of the thalamus?
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.
What is treatment protocol for Parkinson’s disease?
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)
