Systemic Disease in Neurology

What are the CNS symptoms of hyperthyroidism

Increased metabolic and adrenergic activity causes anxiety, tremor, and hyperreflexia.

What is thyroid storm

Severe thyrotoxic decompensation causes high fever, tachyarrhythmia, delirium, and coma.

What is chronic thyrotoxic myopathy

Chronic progressive → Excess thyroid hormone increases protein catabolism, causing progressive proximal muscle weakness with normal CK

What is thyrotoxic peripheral neuropathy

Subacute → sensory dominant → Thyroid-associated axonal dysfunction causes distal numbness and paresthesia.

What is Graves ophthalmopathy

Autoimmune orbital inflammation causes proptosis, diplopia, and restrictive ophthalmoplegia.

What are the CNS symptoms of hypothyroidism

Slows brain metabolism, causing cognitive slowing and depression.

What is myxedema coma

Thyroid decompensation causes hypothermia, bradycardia, hypotension, and altered consciousness.

What is Hoffmann syndrome

Hypothyroid myopathy; presents with muscle stiffness, pseudohypertrophy, and delayed reflex relaxation (Woltman sign); high CK

What is hypothyroid entrapment neuropathy

Mucopolysaccharide accumulation compresses peripheral nerves, frequently causing carpal tunnel syndrome.

How does high cortisol affect the CNS

Alters hippocampal and prefrontal plasticity, impairing cognition and mood.

What causes steroid-induced psychosis

High-dosage corticosteroid use can trigger acute hallucinations, delusions, and severe mood changes.

What is glucocorticoid myopathy

High glucocorticoid cause progressive, painless proximal weakness due to type II fiber atrophy.

What is an Addisonian crisis

Acute cortisol deficiency leads to severe hypotension, encephalopathy, delirium, and seizures.

What is the Wernicke syndrome triad

Ophthalmoplegia, ataxia, and altered consciousness from thiamine def

What is Korsakoff syndrome

Severe anterograde and retrograde amnesia with confabulation.

What are the MRI findings in Wernicke-Korsakoff syndrome

T2/FLAIR hyperintensities in the mammillary bodies and median thalami.

What is subacute combined degeneration

Vitamin B12 deficiency → demyelinates spinal cord columns, causing sensory ataxia (from loss of vibration/proprioception of feet > leg > trunk) and spastic paraparesis

What is pyridoxine deficiency neuropathy

Isoniazid therapy → vitamin B6 deficiency; presenting as a sensory polyneuropathy with burning pain.

What is pyridoxine toxicity

Sensory ganglionopathy resulting in severe ataxia and areflexia from high B6

What is pellagra

Niacin deficiency; impairs cellular energy metabolism, causing dermatitis, diarrhea, dementia, and death (4 Ds)

What are the mechanisms of Neuro-SLE

Damages the nervous system via autoantibodies, neuroinflammation, and thrombosis.

What is vasculitic neuropathy

Inflammation of the vasa nervorum causes nerve ischemia, presenting as painful mononeuritis multiplex.

What is rheumatoid atlantoaxial subluxation

Synovial pannus destroys cervical joints, leading to spinal cord compression and myelopathy.

What are the PNS manifestations of Sjögren disease

Autoimmune inflammation of sensory ganglia leads to sensory ganglionopathy and sensory ataxia.

What are the CNS manifestations of Behçet disease

Multisystem vasculopathy targets the brainstem and venous sinuses, causing ataxia and thrombosis.

What is neurosarcoidosis

Noncaseating granulomatous inflammation affects nervous tissue, causing cranial neuropathies and meningitis.

How does paroxysmal nocturnal hemoglobinuria cause stroke

PIGA gene mutation causes complement-mediated hemolysis and a severe prothrombotic state.

What causes stroke in thrombotic thrombocytopenic purpura

ADAMTS13 deficiency leads to ultra-large vWF multimers, microthrombi, and cerebral ischemia.

How does heparin-induced thrombocytopenia cause stroke

Anti-PF4/heparin antibodies cause widespread platelet activation and stroke despite thrombocytopenia.

What is paraproteinemic neuropathy

Monoclonal immunoglobulins damage peripheral nerves through direct autoantibody binding or protein deposition.