Chiari malformation (CM) is a structural defect in the cerebellum, characterized by a downward displacement of one or both cerebellar tonsils through the foramen magnum (the opening at the base of the skull). CMs can cause headaches, difficulty swallowing, vomiting, dizziness, neck pain, unsteady gait, poor hand coordination, numbness and tingling of the hands and feet, and speech problems. Less often, people may experience ringing or buzzing in the ears, weakness, slow heart rhythm, or fast heart rhythm, curvature of the spine (scoliosis) related to spinal cord impairment, abnormal breathing, such as central sleep apnea, characterized by periods of breathing cessation during sleep, and, in severe cases, paralysis.This can sometimes lead to non-communicating hydrocephalus as a result of obstruction of cerebrospinal fluid (CSF) outflow. The cerebrospinal fluid outflow is caused by phase difference in outflow and influx of blood in the vasculature of the brain. The malformation is named for Austrian pathologist Hans Chiari. A type II CM is also known as an Arnold–Chiari malformation in honor of Chiari and German pathologist Julius Arnold. Signs and symptoms
Findings are due to brain stem and lower cranial nerve dysfunction. Onset of symptoms are less likely to be present during adulthood in most patients. Younger children generally have a substantially different presentation of clinical symptoms from older children. Younger children are more likely to have a more rapid neurological degeneration with profound brain stem dysfunction over several days. Neurogenic dysphagia: Difficulty swallowing. Seen by poor feeding in patient. Cyanosis: Bluish discoloration of skin while feeding.
Public Citizen Health Research Group, another patient advocacy group, opposed the reintroduction.On June 7, 2002, the FDA announced the approval of a supplemental New Drug Application (sNDA) that allows restricted marketing of Lotronex (alosetron hydrochloride), to treat only women with severe diarrhea-predominant irritable bowel syndrome (IBS). The strict prescribing guidelines initially introduced in 2002 were relaxed slightly in 2016, enabling electronic prescriptions among other benefits. It is not known whether alosetron has been filed for registration in the EU. GSK sold Lotronex to the Californian corporation Prometheus in late 2007.Since 2015, generic versions of alosetron have been available in the US, sold by a number of different companies including Actavis Pharma Company, Prometheus Laboratories and Sebela Pharmaceuticals Inc

Criticism of the FDA
In 2001, the editor of the renowned medical journal The Lancet, Richard Horton, criticized the FDAs handling of alosetron in an unusually sharp language. Horton argued that the treatment of a non-fatal condition did not justify the use of a drug with potentially lethal side effects, and that the FDA should have revoked the approval for alosetron sooner when postmarketing surveillance revealed that many patients had suffered constipation necessitating surgical intervention and ischaemic colitis. He asserted that FDA officials were improperly motivated to maintain and reinstate the approval for alosetron because of the extent to which the FDAs Center for Drug Evaluation and Research is funded by user fees paid by pharmaceutical manufacturers, and that the reinstatement of alosetron was negotiated in confidential meetings with representatives of GlaxoSmithKline.