Exploring CNS Involvement in Pain Insensitivity in Hereditary Sensory and Autonomic Neuropathy Type 4: Insights from Tc-99m ECD SPECT Imaging.

Hereditary sensory and autonomic neuropathy type 4 (HSAN4), also known as congenital insensitivity to pain with anhidrosis (CIPA), is a rare genetic disorder caused by NTRK1 gene mutations, affecting nerve growth factor signaling. This study investigates the central nervous system's (CNS) involvement and its relation to pain insensitivity in HSAN4. We present a 15-year-old girl with HSAN4, displaying clinical signs suggestive of CNS impact, including spasticity and a positive Babinski's sign. Using Technetium-99m ethyl cysteinate dimer single-photon emission computed tomography (Tc-99m ECD SPECT) imaging, we discovered perfusion deficits in key brain regions, notably the cerebellum, thalamus, and postcentral gyrus. These regions process pain signals, providing insights into HSAN4's pain insensitivity. This study represents the first visualization of CNS perfusion abnormality in an HSAN4 patient. It highlights the intricate relationship between the peripheral and central nervous systems in HSAN4. The complexity of HSAN4 diagnosis, involving potential unidentified genes, underscores the need for continued research to refine diagnostic approaches and develop comprehensive treatments.

Effects of intravascular photobiomodulation on motor deficits and brain perfusion images in intractable myasthenia gravis: A case report.

BACKGROUND: Myasthenia gravis (MG) is an autoimmune disorder caused by neuromuscular junction failure characterized by muscle weakness and fatigability. We herein report a case of MG that received intravascular laser irradiation of blood (ILIB) interventions and regained muscle power and better quality of life. To our knowledge, no previous study has investigated the benefits of ILIB treatment on patients with MG. We also evaluated the changes in brain perfusion scan and the MG activities of daily living (MG-ADL) and quantitative MG (QMG) scales. CASE SUMMARY: A 59-year-old man presented to our outpatient hospital experiencing ptosis, diplopia, fibromyalgia, muscle fatigue, and fluctuating weakness in his limbs for 1 year. Based on his history, physical examination, and laboratory investigations, the final diagnosis was a flare-up of MG with poor endurance and muscle fatigue. The patient agreed to receive ILIB. Brain single-photon emission computed tomography (SPECT) was performed both before and after ILIB therapy. After receiving three courses of ILIB, the brain SPECT images showed greatly increased perfusion of the frontal lobe and anterior cingulate gyri. The patient's MG-ADL scale score decreased markedly from 17/24 to 3/24. The QMG scale score also decreased remarkably from 32/39 to 9/39. The symptoms of MG became barely detectable and the patient was able to perform his activities of daily living and regain muscle power. CONCLUSION: ILIB might have beneficial effects on MG, and brain SPECT images provided direct evidence of a positive correlation between ILIB and clinical performance.