Amifampridine is used as a drug, predominantly in the treatment of a number of rare muscle diseases. The free base form of the drug has been used to treat congenital myasthenic syndromes and Lambert–Eaton myasthenic syndrome (LEMS) through compassionate use programs since the 1990s and was recommended as a first line treatment for LEMS in 2006, using ad hoc forms of the drug, since there was no marketed form. Around 2000 doctors at Assistance Publique – Hôpitaux de Paris created a phosphate salt form, which was developed through a series of companies ending with BioMarin Pharmaceutical which obtained European approval in 2009 under the trade name Firdapse, and which licensed the US rights to Catalyst Pharmaceuticals in 2012. As of January 2017, Catalyst and another US company, Jacobus Pharmaceutical, which had been manufacturing and giving it away for free since the 1990s, were both seeking FDA approval for their iterations and marketing rights. Amifampridine phosphate has orphan drug status in the EU for Lambert–Eaton myasthenic syndrome and Catalyst holds both an orphan designation and a breakthrough therapy designation in the US. In May 2019 the U.S. Food and Drug Administration (FDA) approved amifampridine tablets under the trade name Ruzurgi for the treatment of Lambert-Eaton myasthenic syndrome (LEMS) in patients 6 to less than 17 years of age. This is the first FDA approval of a treatment specifically for pediatric patients with LEMS. The FDA granted the approval of Ruzurgi to Jacobus Pharmaceutical.
Congenital dermal sinus is an uncommon form of cranial or spinal dysraphism. It occurs in 1 in 2500 live births. It occurs as a dermal indentation, found along the midline of the neuraxis and often presents alongside infection and neurological deficit. Congenital dermal sinus form due to a focal failure of dysjunction between the cutaneous ectoderm and neuroectoderm during the third to eight week of gestation. Typically observed in the lumbar and lumbosacral region, congenital dermal sinus can occur from the nasion and occiput region down.Early diagnosis and treatment is crucial for cases of congenital dermal sinus. It ensures that neurological condition does not degrade and prevents infection. Diagnosis can be confirmed through the use of advanced neuroimaging to observe the tract and associated lesions. Embryogenesis
During normal development, cutaneous ectoderm separates from neuroectoderm to allow for the insertion of mesoderm. That is, the skin separates from the tissue of the spinal cord to allow proper formation of the vertebral column. In cases of congenital dermal sinus there is a failure in this process, resulting in formation of a persistent connection between the skin and neural tissue. This manifests as a tract extending from the surface of the skin to the spinal cord lined with stratified squamous epithelium, surrounded by dermal and neurological tissue. The tract may terminate in the deep fascia, or even make contact with neural elements.