Diseases of the Spinal Cord​

An ischemic stroke (also known as cerebrovascular accident) is an acute neurologic injury that occurs as a result of brain ischemia; this condition may be due to cerebral blood vessel occlusion by thrombosis or embolism, or rarely due to systemic hypoperfusion. The clinical presentation includes neurologic symptoms with varying degrees of motor and sensory loss corresponding to the area of the brain that is affected and the extent of tissue damage. Diagnosis is made by physical examination and imaging. Management is ideally with thrombolytic therapy to restore blood flow, depending on the time frame and clinical situation. Long-term rehabilitation with physical, occupational, and speech therapies is important after the acute event.

Spinal cord injuries are complex injuries that involve damage to the neural tissue within the spinal canal. Spinal cord injuries are commonly the result of trauma. Clinical presentation varies depending on the site of injury and on whether the injury is complete or incomplete. Diagnosis is by clinical exam and imaging. Management is 2-fold, with immediate supportive care and stabilization of spine followed by long-term rehabilitation with physiotherapy and treatment of complications. Spinal cord injuries are associated with multisystem complications.

Spinal disk herniation (also known as herniated nucleus pulposus) describes the expulsion of the nucleus pulposus through a perforation in the annulus fibrosus of the intervertebral disk. Spinal disk herniation is an important pain syndrome with the potential for neurologic impairment and is most commonly caused by degenerative disk disease. Clinical presentation depends on the presence or absence of spinal cord or nerve root compression and the downstream neurologic sequelae (e.g., radicular pain, muscle weakness, sensory deficit, reflex deficit). Diagnosis is initially clinical and can be confirmed with diagnostic imaging (e.g., MRI). Management can range from conservative to surgical, depending on the situation.

The spinal cord is the major conduction pathway connecting the brain to the body; it is part of the CNS. The spinal cord is divided into cervical, thoracic, lumbar, and sacral regions, though because the spinal cord is shorter than the vertebral column, these regions do not line up with their corresponding vertebral levels. In cross section, the spinal cord is divided into an H-shaped area of gray matter (consisting of synapsing neuronal cell bodies) and a surrounding area of white matter (consisting of ascending and descending tracts of myelinated axons). Like the brain, the spinal cord is surrounded by 3 layers of connective tissue, collectively known as the meninges; these layers are the dura mater, arachnoid mater, and pia mater. The spinal cord is supplied by 1 anterior and 2 posterior spinal arteries.

The vertebral column is the most important anatomical and functional axis of the body, consisting of 7 cervical, 12 thoracic, and 5 lumbar vertebrae and limited cranially by the skull and caudally by the sacrum. The vertebral column provides structural support and protection for the spinal cord, which is housed in the spinal canal. The vertebral column and the spinal cord may be affected by various diseases, in which different imaging methods are important for correct diagnosis and management. Radiographs and CT scans are useful in evaluating bony structures, especially in excluding fractures and checking hardware. Additionally, CT scans also provide information on soft tissues. MRI is performed for evaluation of tumors, infection, disk herniations, and other soft tissue abnormalities including acute ligamentous or spinal cord injury.

Folate and vitamin B12 are 2 of the most clinically important water-soluble vitamins. Deficiencies can present with megaloblastic anemia, GI symptoms, neuropsychiatric symptoms, and adverse pregnancy complications, including neural tube defects. Deficiencies are more likely to occur in specific patient populations, especially B12 deficiencies, which are more common in patients on vegan diets and in those with conditions related to the stomach and/or terminal ileum that affect absorption. These vitamins generally do not cause toxicity when consumed in excess amounts, even in supplemental form, as they are effectively excreted by the kidneys.

Fat-soluble vitamins are absorbed and stored in adipose tissue (fat) and the liver. These vitamins can be released from storage and used when necessary. The 4 important fat-soluble vitamins are A, D, E, and K. Each vitamin has its own function, and deficiencies can lead to significant clinical manifestations. Diagnosis of deficiencies is by clinical presentation and lab testing, and management of vitamin deficiency is with supplementation. Because these vitamins are fat-soluble and stored in the body, overuse of supplemental vitamins may lead to toxicity and adverse effects, especially with vitamins A and D.

Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease that leads to demyelination of the nerves in the CNS. Young women are more predominantly affected by this most common demyelinating condition. The etiology of MS is unclear; however, both genetic and environmental factors are believed to play a role. The clinical presentation varies widely depending on the site of lesions, but typically includes neurological symptoms that affect vision, motor functions, sensation, and autonomic function. The diagnosis is made via MRI of the entire CNS (brain and spine) as well as CSF examination. Management involves corticosteroids for acute exacerbations and disease-modifying agents to reduce these exacerbations and slow disease progression. The average life expectancy of individuals with MS is decreased by 5–10 years.

The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. The vertebral column is the foundation for the trunk, provides an attachment for muscles and ligaments, and protects the spinal cord and nerve roots.

An ischemic stroke (also known as cerebrovascular accident) is an acute neurologic injury that occurs as a result of brain ischemia; this condition may be due to cerebral blood vessel occlusion by thrombosis or embolism, or rarely due to systemic hypoperfusion. The clinical presentation includes neurologic symptoms with varying degrees of motor and sensory loss corresponding to the area of the brain that is affected and the extent of tissue damage. Diagnosis is made by physical examination and imaging. Management is ideally with thrombolytic therapy to restore blood flow, depending on the time frame and clinical situation. Long-term rehabilitation with physical, occupational, and speech therapies is important after the acute event.

Spinal muscular atrophy (SMA) is a spectrum of autosomal recessive syndromes characterized by progressive proximal muscle weakness and atrophy, possibly due to degeneration of the anterior horn cells in the spinal cord and motor nuclei in the lower brainstem. There are 5 clinical types of SMA, each with a distinctive clinical presentation unified by motor weakness. The earlier presentations are associated with more severe motor weakness affecting a child’s ability to reach the developmental milestones of sitting or walking. In the more severe types, breathing and swallowing may also become difficult as the disease progresses. The prognosis of SMA is poor. In the less severe types, adults have a normal lifespan. The initial diagnosis is made clinically and confirmed using genetic testing. Management is mostly supportive although novel therapies are being developed. The prognosis depends on the clinical type.

Spinal stenosis is the progressive narrowing of the central spinal canal, intervertebral foramen, and lateral recess, leading to compression of the nerve root. Spinal stenosis can occur in the cervical, thoracic, and lumbar spine and is commonly caused by degenerative bone disease (mostly affecting the elderly). Patients present with pain, weakness, numbness, and tingling in the neck or lower back, which may radiate to the legs and buttocks. Clinical examination shows symptom improvement with spinal flexion and symptom deterioration with spinal extension. The diagnosis is confirmed with MRI. Conservative management includes analgesic/antiinflammatory medications and physiotherapy. Decompression surgery (laminectomy) is considered in advanced cases, or if conservative management fails.

Blood supply to the brain can be divided into an anterior and a posterior circulation, which interconnect to form the circle of Willis. The anterior circulation is derived from the internal carotid arteries and consists mainly of the anterior and middle cerebral arteries. The posterior circulation is derived from the vertebral arteries and consists primarily of the cerebellar and posterior cerebral arteries. The primary venous drainage of the brain occurs via the internal jugular vein.