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Tethered spinal cord syndrome
Spinocerebellar ataxia (NORD)
Transient ischemic attack
Concussion and traumatic brain injury
Shaken baby syndrome
Early infantile epileptic encephalopathy (NORD)
Idiopathic intracranial hypertension
Cavernous sinus thrombosis
Lewy body dementia
Normal pressure hydrocephalus
Restless legs syndrome
Opsoclonus myoclonus syndrome (NORD)
Central pontine myelinolysis
Acute disseminated encephalomyelitis
JC virus (Progressive multifocal leukoencephalopathy)
Adult brain tumors
Acoustic neuroma (schwannoma)
Pediatric brain tumors
Cauda equina syndrome
Treponema pallidum (Syphilis)
Vitamin B12 deficiency
Cavernous sinus thrombosis
von Hippel-Lindau disease
Amyotrophic lateral sclerosis
Spinal muscular atrophy
Thoracic outlet syndrome
Carpal tunnel syndrome
Lambert-Eaton myasthenic syndrome
Congenital neurological disorders: Pathology review
Headaches: Pathology review
Seizures: Pathology review
Cerebral vascular disease: Pathology review
Traumatic brain injury: Pathology review
Spinal cord disorders: Pathology review
Dementia: Pathology review
Central nervous system infections: Pathology review
Movement disorders: Pathology review
Neuromuscular junction disorders: Pathology review
Demyelinating disorders: Pathology review
Adult brain tumors: Pathology review
Pediatric brain tumors: Pathology review
Neurocutaneous disorders: Pathology review
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Tanner Marshall, MS
Chiari malformations are a group of conditions where the cerebellum of the brain extends down into the spinal canal and results in the blockage of the normal flow of cerebrospinal fluid.
The cerebellum, or "little brain", is divided into two hemispheres which are separated by a narrow worm-like structure in the middle called the vermis.
Directly beneath the hemispheres are two smaller lobes called cerebellar tonsils.
Normally, the cerebellum and cerebellar tonsils sit right above the foramen magnum which is the opening at the base of the skull through which the spinal cord passes through.
The cerebellum is contained within the posterior fossa or floor of the back of the skull, which also contains the medulla oblongata.
The cerebellum controls balance, posture, and helps to initiate as well as fine-tune voluntary motor activity - think about the fancy finger work of a piano player or the vocal cords of a singer - that’s the cerebellum in action.
The medulla, on the other hand, controls autonomic functions such as breathing and blood pressure, as well as reflexes such as coughing, vomiting, gagging, and swallowing.
Now, there’s also a set of four interconnected cavities in the brain called ventricles, each of which create and circulate cerebrospinal fluid.
Highest up, are two C-shaped lateral ventricles that lie deep in each cerebral hemisphere.
The two lateral ventricles drain their cerebrospinal fluid into the third ventricle, which is a narrow, funnel-shaped, cavity at the center of the brain.
The third ventricle makes a bit more cerebrospinal fluid and then sends all of the cerebrospinal fluid to the fourth ventricle via the cerebral aqueduct.
Chiari malformation is a structural defect in the brain which occurs when the cerebellum herniates in the foramen magnum due to craniovertebral junction anomalies. This can cause pressure on the spinal cord and other parts of the brain. There are different types of Chiari malformations, but the common ones are type I and II. Type I Chiari malformation occurs when there is the herniation of only the cerebellar tonsils and is associated with syringomyelia. Type II Chiari malformation (also called Arnold Chiari malformation) occurs when there is herniation of both the cerebellar tonsils and the vermis and is associated with myelomeningocele.
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