Sweating is almost completely absent with this disorder. Intellectual disability is usually present. Type 4, congenital insensitivity to pain with anhidrosis (CIPA), is an autosomal recessive condition and affected infants present with episodes of hyperthermia unrelated to environmental temperature, anhidrosis and insensitivity to pain. Palmar skin is thickened and charcot joints are commonly present. NCV shows motor and sensory nerve action potentials to be normal. The histopathology of peripheral nerve biopsy reveals absent small unmyelinated fibers and mitochondria are abnormally enlarged. Management of Hereditary sensory and autonomic neuropathy Type 4:
Treatment of manifestations: Treatment is supportive and is best provided by specialists in pediatrics, orthopedics, dentistry, ophthalmology, and dermatology. For anhidrosis: Monitoring body temperature helps to institute timely measures to prevent/manage hyperthermia or hypothermia. For insensitivity to pain: Modify as much as reasonable a childs activities to prevent injuries. Inability to provide proper immobilization as a treatment for orthopedic injuries often delays healing; additionally, bracing and invasive orthopedic procedures increase the risk for infection. Methods used to prevent injuries to the lips, buccal mucosa, tongue, and teeth include tooth extraction, and/or filing (smoothing) of the sharp incisal edges of teeth, and/or use of a mouth guard. Skin care with moisturizers can help prevent palmar and plantar hyperkeratosis and cracking and secondary risk of infection; neurotrophic keratitis is best treated with routine care for dry eyes, prevention of corneal infection, and daily observation of the ocular surface. Interventions for behavioral, developmental and motor delays, as well as educational and social support for school-age children and adolescents, are recommended.
Lastly, the frontal bone is divided into two, rotated and attached to the supraorbital bar causing a nude area (craniectomy) between the parietal bone and frontal bone. Bone will eventually regenerate since the dura mater lies underneath (the dura mater has osteogenic capabilities). This results in an advancement and straightening of the forehead. Floating forehead technique
The so-called floating forehead technique combined with the remodelling of the supraorbital bar is derived from the fronto-supraorbital advancement and remodelling. The supraorbital bar is remodelled as described above. The frontal bone is split in two pieces. Instead of using both pieces as in fronto-supraorbital advancement and remodelling, only one piece is rotated and attached to the supraorbital bar. This technique also leaves a craniectomy behind. Other
SuturectomyThe simplest form of surgery for trigonocephaly was suturectomy. However, as this technique was insufficient to correct the deformities, it is not used anymore. Distraction osteogenesisDistraction osteogenesis is based on creating more cranial space for the brain by gradually moving the bones apart. This can be achieved by using springs. Minimal invasive endoscopic surgeryThese approaches are 2D solutions for a 3D problem, therefore the results are not optimal. Distraction osteogenesis and minimal invasive endoscopic surgery are yet in experimental phase. Outcomes
Surgical
Trigonocephaly seems to be the most compliant form of craniosynostosis for surgery. Because of standardization of current surgical approaches there is no surgical mortality and complications are few to none. The simple suturectomy is presently insufficient to adjust the complicated growth restrictions caused by metopic synostosis.