Other Diseases: Hydrocephalus, Neuromuscular Disease, Plexopathy and Mononeuritis

Neuropathy is a nerve pathology presenting with sensory, motor, or autonomic impairment secondary to dysfunction of the affected nerve. The peripheral nerves (outside the brain and spinal cord), are derived from several plexuses, with the brachial and lumbosacral plexuses supplying the major innervation to the extremities. Mononeuropathy (affecting a single nerve) and plexopathy (affecting the plexus) can occur from trauma, compression, and systemic diseases. The clinical presentation varies according to location, type of nerves affected, and cause of the damage. Diagnosis requires a thorough physical examination, and diagnostic tests include laboratory tests, imaging and a confirmatory nerve conduction study, and electromyography. Management depends on the etiology but centers around physical therapy, supportive care, and treatment of underlying issues.

The brachial plexus is a network of nerves that originate from the lower cervical and upper thoracic nerve roots. The causes of brachial plexopathies include traumatic injuries, birth-related injuries, iatrogenic procedures, neoplastic processes, and previous treatment with radiation. Patients present with sensory and motor deficits related to the site of the lesion and the nerves involved. Diagnosis is made based on clinical findings, imaging, and electrodiagnostic studies. Treatment is related to the underlying cause and may be medical or surgical.

Normal pressure hydrocephalus (NPH) is a neurodegenerative disorder characterized by the triad of gait abnormalities, dementia, and urinary urgency or incontinence. Normal pressure hydrocephalus can be either idiopathic or secondary to intraventricular or subarachnoid hemorrhage. Symptoms may be similar to those of Alzheimer and Parkinson's diseases. Diagnosis of NPH is clinical, in addition to lumbar puncture testing and neuroimaging. Management is with surgical shunt placement to drain excess CSF from the cerebral ventricles.

Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, is a sporadic or inherited neurodegenerative disease of upper motor neurons (UMNs) and lower motor neurons (LMNs). Amyotrophic lateral sclerosis is the most common progressive motor neuron disease in North America, primarily affecting men and individuals of Caucasian ethnicity. This disease is characterized by the coexistence of UMN and LMN signs and symptoms. The diagnosis is made clinically. Management is supportive and symptomatic, progressing to end-of-life care.

The axilla is a pyramid-shaped space located between the upper thorax and the arm. The axilla has a base, an apex, and 4 walls (anterior, medial, lateral, posterior). The base of the pyramid is made up of the axillary skin. The apex is the axillary inlet, located between the 1st rib, superior border of the scapula, and clavicle. The apex houses various vessels and nerves, including the axillary artery and its branches, the axillary vein and its tributaries, the branches of the brachial plexus, and the axillary lymph nodes.

Hydrocephalus is a potentially life-threatening condition caused by the excess accumulation of cerebrospinal fluid (CSF) within the ventricular system. Hydrocephalus can be classified as communicating, which is caused by either impaired CSF absorption or excess CSF production; or non-communicating, which is caused by a structural blockage in CSF flow. The causes of hydrocephalus can be congenital or acquired. The clinical presentation is often nonspecific with symptoms including headache, behavioral changes, developmental delays, or nausea and vomiting. If the hydrocephalus is congenital or acquired at a young age, infants often present with macrocephaly. Diagnosis is confirmed with neuroimaging (ultrasound, computed tomography of the head, or magnetic resonance imaging) showing ventriculomegaly. Treatment is most commonly surgical with the placement of a CSF shunt.