General Neurology Flashcards
What is an Arnold-Chiari malformation?
Downwards displacement, or herniation of the cerebellar tonsils through the foramen magnum.
How can an Arnold-Chiari malformation be caused?
Congenital or Trauma
What are the features of an Arnold-Chiari malformation?
Brainstem and lower cranial nerve dysfunction.
Non-communicating hydrocephalus - may develop as a result of obstruction of cerebrospinal fluid outflow.
Headache, difficulty swallowing, vomiting, dizziness, neck pain, unsteady gait, poor hand coordination, numbness and tingling to hands and feet, speech problems.
Syringomyelia - cyst forming in the spinal cord, can cause loss of sensation, paralysis and weakness in back, shoulders and extremities.
How is an Arnold-Chiari malformation diagnosed?
MRI head
How is an Arnold-Chiari malformation treated?
Decompressive surgery
What type of lesion causes peripheral ataxia?
Cerebellar hemisphere lesions (Finger-nose ataxia)
What type of lesion causes gait ataxia?
Cerebellar vermis lesions
What is ataxia telangiectasia?
An autosomal recessive disorder caused by a defect in an ATM gene.
What are the features of ataxia telangiectasia?
Typically presents in early childhood 1-5 years.
Abnormal movements (Cerebellar ataxia)
Telangiectasia (Spider angiomas)
IgA deficiency - recurrent infections
10% risk of malignancy
What is autonomic dysreflexia?
Clinical syndrome occurring with spinal cord injury at or above T6 spinal level.
Afferent signals (from faecal impaction or urinary retention) cause an unopposed (due to lesion) sympathetic spinal reflex.
Unbalanced physiological response: Extreme hypertension, flushing, sweating (above lesion), agitation and potentially haemorrhagic stroke.
The management is removal of the stimulus and treatment of life-threatening hypertension or bradycardia.
What is the cause of brown-sequard syndrome?
Caused by lateral hemisection of the spinal cord
What are the features of brown-sequard syndrome?
Ipsilateral weakness below the lesion
Ipsilateral loss of proprioception and vibration sensation
Contralateral loss of pain and temperature sensation
What is cataplexy?
Sudden and transient loss of muscular tone caused by strong emotion (e.g. laughter, being frightened)
Features include buckling knees to collapse
What disease is associated with cataplexy?
Narcolepsy
What space is filled by the CSF?
Space between the arachnoid mater and pia mater (covering surface of the brain)
What is the approximate volume of circulating CSF?
150 ml
Where is the CSF produced?
500 ml
Ependymal cells in the choroid plexus (70%)
Blood vessels (30%)
Where is CSF reabsorbed?
Arachnoid granulation projecting into the venous sinuses
What is the circulatory path of the CSF?
- Lateral ventricles (via foramen of Munro)
- 3rd ventricle
- Cerebral aqueduct (aqueduct of Sylvius)
- 4th ventricle (via foramina of Magendie and Luschka)
- Subarachnoid space
- Reabsorbed into the venous system via arachnoid granulations into the superior sagittal sinus.
What is the composition of CSF?
Glucose: 50-80mg/dl
Protein: 15-40mg/dl
Red blood cells: Nil
White blood cells: 0-3 cells/mm^3
What is Charcot-Marie-Tooth disease?
Most common hereditary peripheral neuropathy. Results in predominantly motor loss.
What is the presentation of Charcot-Marie-Tooth disease?
Sprained ankles Foot drop High-arched feet Hammer toes Distal muscle weakness Distal muscle atrophy Hyporeflexia Stork leg deformity
What is the treatment of Charcot-Marie-Tooth disease?
Physical and occupational therapy.
What is complex regional pain syndrome (CRPS)?
Neurological and related symptoms causing lasting pain, typically occurring following surgery or a minor injury.
Reflex sympathetic dystrophy (worse, long lasting pain) and causalgia (severe burning pain)
Women 3 > 1 Men
