Neurofibromatosis

Neurofibromatosis Definition: an autosomal dominant genetic disorder affecting cells of neural crest origin (e.g. melanocytes, craniofacial cartilage and bone, smooth muscle, peripheral and enteric neurones and glia), resulting in development of multiple neurocutaneous tumours. Type 1 neurofibromatosis (NF1, von Recklinghausen's disease)- characterised by peripheral and spinal neurofibromas, multiple café-au-lait spots, freckling, optic nerve glioma, Lisch … Continue reading Neurofibromatosis

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Wernicke’s Encephalopathy

Wernicke's Encephalopathy Definition: Thiamine deficiency with a classical triad of confusion, ataxia, and ophthalmoplegia. Aetiology/ risk factors: -Thiamine (Vitamin B1) deficiency -inadequate dietary intake -reduced GI absorption -impaired utilisation = focal areas of brain damage, including periaqueductal punctate haemorrhages -Often seen in chronic alcoholism -Also: eating disorders, malnutrition, prolonged vomiting e.g. with chemo, GI malignancy, … Continue reading Wernicke’s Encephalopathy

Hydrocephalus

 Hydrocephalus Definition: enlargement of the cerebral ventricular system. Subdivisable into obstructive and non-obstructive, or communicating and non-communicating. Aetiology/ risk factors: -Abnormal accumulation of CSF in the ventricles, leading to raised intracranial pressure, caused by: Impaired outflow of CSF from the ventricular system (obstructive/ non-communicating): -lesions of the third ventricle, fourth ventricle, cerebral aqueduct (inc. TB, neurocysticercosis) … Continue reading Hydrocephalus

Guillain-Barre Syndrome

Guillain-Barré Syndrome (GBS) Definition: an acute, predominantly motor, inflammatory demyelinating polyneuropathy Aetiology/ risk factors: -occurs a few weeks (1-3) after an infection e.g. Camylobacter jejuni (from undercooked chicken) CMV, mycoplasma, herpes zoster, HIV, EBV post-vaccinations -may occur with lymphoma or Hodgkin's disease -infective trigger causes antibodies which react with self-antigen on myelin or neurones -no cause found in 40% (idiopathic) … Continue reading Guillain-Barre Syndrome

Myasthenia Gravis

Myasthenia Gravis Definition: an autoimmune disease affecting the neuromuscular junction producing weakness of skeletal muscles Aetiology/ risk factors: -Mediated by autoantibodies against the nicotinic acetylcholine receptors (AChR), interfering with the neuromuscular transmission via depletion of working post-synaptic receptor sites. -Both B and T cells are implicated. Associations: < 50 years- women, other autoimmune diseases, thymic … Continue reading Myasthenia Gravis