Chapter 10: Infectious and Inflammatory Neurological Disorders

Meningitis, characterized by inflammation of the meninges surrounding the central nervous system, presents with the classic triad of fever, headache, and neck stiffness, with bacterial forms requiring emergent antibiotic therapy after cerebrospinal fluid analysis and blood cultures. Encephalitis involves inflammation of brain parenchyma itself and frequently produces altered consciousness, seizures, and focal neurological deficits, with herpes simplex virus being the most common causative agent in sporadic cases. Herpes zoster results from varicella-zoster virus reactivation and presents with dermatomal vesicular rash preceded by neuropathic pain, with postherpetic neuralgia representing a significant long-term complication in untreated older populations. Trigeminal neuralgia manifests as severe, paroxysmal facial pain triggered by tactile stimuli and responds to anticonvulsant medications as first-line therapy. Bell's palsy represents acute lower motor neuron facial paralysis likely related to herpes simplex reactivation, requiring corticosteroid treatment and meticulous eye care to prevent corneal complications. Guillain-Barré syndrome is an acute immune-mediated polyradiculoneuropathy presenting with ascending paralysis that demands urgent hospitalization due to respiratory failure risk, treated with intravenous immunoglobulin or plasmapheresis. Myasthenia gravis is an autoimmune disorder targeting acetylcholine receptors at the neuromuscular junction, producing fatigable weakness that improves with rest and responds to anticholinesterase agents and immunosuppressive therapies. Multiple sclerosis is a chronic demyelinating disorder of the central nervous system predominantly affecting young adults, diagnosed through demonstration of lesions disseminated in both space and time on magnetic resonance imaging, managed with disease-modifying therapies and symptomatic treatments focused on spasticity, fatigue, and neuropathic pain management.