Abstract Hereditary spastic paraplegias (HSPs) represent a large and heterogeneous group of inherited disorders, presenting with a phenotype that is predominated by lower limb spasticity and weakness, often accompanied by…
Abstract Purine metabolism encompasses the metabolic pathways involved in the synthesis, interconversion, salvage, and degradation of purine-based nucleosides and nucleotides. These metabolic pathways are involved in many essential cellular processes,…
Abstract Creatine is synthetized from two amino acids, arginine and glycine, in the kidney, liver, and pancreas. Two enzymes that are involved in the synthesis of creatine are L-arginine:glycine amidinotransferase…
Abstract Bile acids are synthesized via the classic pathway initiated by cholesterol 7-alpha-hydroxylase (CYP7A1) or via alternate pathways, one of which is initiated by sterol 27-hydroxylase (CYP27). Cerebrotendinous xanthomatosis (CTX)…
Abstract Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the brain. The primary precursor of GABA is glutamate, the major excitatory neurotransmitter in the brain. Glutamate is converted into…
Abstract Biotin–thiamin-responsive basal ganglia disease (BTBGD) is a reversible neurodegenerative disorder that is widely underdiagnosed. Chapter 25 Vitamin-Responsive Disorders: Biotin–Thiamine-Responsive Basal Ganglia Disease and Movement Disorders Albert L. Misko and…
Abstract Ataxia with vitamin E deficiency (AVED) was first described in 1981 by Burck et al. [1] as a progressive cerebellar ataxia in a 12-year-old boy with low vitamin E…
Abstract DNAJC12 deficiency is a recently described form of hyperphenylalaninemia (HPA) [1]. HPA represents a metabolic condition caused by a deficiency in either phenylalanine (Phe) hydroxylase (PAH) or in one…
Abstract Muscular tone and movements are highly dependent on the communication of neurons and muscle cells. This complex process is achieved by neurotransmitters, chemical substances synthesized and stored in presynaptic…
Abstract During the evaluation of a patient with a movement disorder, advanced neuroimaging is often obtained to narrow the diagnostic possibilities and also to assess the status of what is…
