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Amyotrophic lateral sclerosis
von Hippel-Lindau disease
Acoustic neuroma (schwannoma)
Adult brain tumors
Pediatric brain tumors
Transient ischemic attack
Cavernous sinus thrombosis
Spinocerebellar ataxia (NORD)
Tethered spinal cord syndrome
Lewy body dementia
Normal pressure hydrocephalus
Acute disseminated encephalomyelitis
Central pontine myelinolysis
JC virus (Progressive multifocal leukoencephalopathy)
Idiopathic intracranial hypertension
Opsoclonus myoclonus syndrome (NORD)
Restless legs syndrome
Early infantile epileptic encephalopathy (NORD)
Cauda equina syndrome
Treponema pallidum (Syphilis)
Vitamin B12 deficiency
Concussion and traumatic brain injury
Spinal muscular atrophy
Carpal tunnel syndrome
Thoracic outlet syndrome
Lambert-Eaton myasthenic syndrome
Adult brain tumors: Pathology review
Central nervous system infections: Pathology review
Cerebral vascular disease: Pathology review
Congenital neurological disorders: Pathology review
Dementia: Pathology review
Demyelinating disorders: Pathology review
Headaches: Pathology review
Movement disorders: Pathology review
Neurocutaneous disorders: Pathology review
Neuromuscular junction disorders: Pathology review
Pediatric brain tumors: Pathology review
Seizures: Pathology review
Spinal cord disorders: Pathology review
Traumatic brain injury: Pathology review
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Amyotrophic Lateral Sclerosis (ALS)
Type I Spinal Muscular Atrophy
At the physician’s office, 55-year-old Mario presents complaining of weakness in his hands and feet. These symptoms have gradually progressed over the past couple of months. At first, he struggled to manipulate small objects like buttoning his shirt. Now he also often stumbles while walking and recently fell down the stairs. In addition, his family mentions that his speech has become slightly slurred. He denies any sensory symptoms, memory loss or any bowel or bladder complaints. Later that day, 43-year-old Donna comes in with difficulty walking. She has fallen several times over the last few weeks. Her past medical history is significant for HIV infection, which was diagnosed a few years ago. On neurologic examination, her pupils are small and irregularly shaped and do not react to light, but constrict with accommodation. The sensations of pressure, vibration, fine touch and proprioception are also reduced throughout the lower extremities. She has a wide-based gait and cannot maintain balance with her eyes closed.
Based on the initial presentation, both Mario and Donna have some form of spinal cord disorder. Okay, let’s talk about physiology first real quick. If we zoom in at a cross-section of the spinal cord, we’ll see that it is composed of both grey and white matter. Grey matter is found within the medial portion of the spinal cord and has two dorsal or posterior horns that contain cell bodies of sensory neurons and two ventral or anterior horns that contain cell bodies of motor neurons. In the center of the grey matter there’s a small cavity called the central canal which is filled with cerebrospinal fluid that provides nutrients and mechanical support. Surrounding the grey matter is white matter, which consists of the axons of various neurons and they are organized into tracts that carry information to and from the brain.
For your exams, there are a few main tracts to remember. First, there’s the spinothalamic tract which is an ascending pathway and it’s divided into two parts. The lateral tract carries sensory information for pain and temperature, while the anterior tract carries information for crude touch, or the sense one has been touched, without being able to localize where they were touched. For this to happen, a first order neuron, found inside a dorsal root ganglion carries sensory input from the skin to the dorsal horn of the spinal cord, where it synapses with the second order neuron. And that neuron ascends 1-2 vertebral levels and decussates or crosses to the opposite side of the spinal cord via an area of white matter called the anterior white commissure. The secondary neuron then ascends up the length of the spinal cord via the spinothalamic tracts, and eventually synapse with a 3rd order neuron located in the ventral posterior nucleus of the thalamus. This 3rd order neuron then sends its axon up to the sensory cortex of the brain, letting you know that there’s a sensory signal.
The spinal cord is a delicate and complex structure that runs from the brain down the center of the back. Some common spinal cord disorders include Spinal cord injury, which occurs when there is damage to the spinal cord from trauma; Spinal cord tumors, which refers to growths that develop within the spinal cord and can cause pressure on the spinal cord; spinal cord infarction, which is the loss of blood flow to the spinal cord, causing damage to the tissue; degenerative spinal disorders, which include conditions such as spinal stenosis, herniated disc, osteoarthritis); and infections and abscesses. Symptoms vary according to etiology but include fever, pain, weakness, loss of sensation, and paralysis.
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