Brain stem interneuronal excitability can be assessed by recording the recovery cycle of the blink reflex and exteroceptive suppression of temporalis muscle activity. Abnormal endogenous pain control mechanisms due to disturbed brain stem interneuronal activity have been implicated in the pathogenesis of tension-type headaches. The blink reflex, exteroceptive suppression of temporalis muscle activity, and the recovery curve of both the R2 component of the blink reflex and the ES2 component of the exteroceptive suppression of the temporalis muscle activity were studied in 20 patients with migraine without aura, 32 patients with tension-type headache, and 20 normal controls. In our study, the blink reflex was elicited by stimulation of the supraorbital nerve; the exteroceptive suppression of the temporalis muscle activity was elicited by applying electrical shocks to the labial commissure, both on the lower and upper sides. The recovery cycle was established by delivering paired shocks at different interstimulus intervals. Comparisons were made between normal control subjects, patients with migraine without aura, and patients with tension-type headache. The latency of R1, R2, and R2', the amplitude and size of the R2 and R2' components of the blink reflex, the latency and duration of the ES1 and ES2 components, and the recovery curve of the ES2 component of the temporalis muscle activity did not differ between groups. However, the recovery curve of the R2 component of the blink reflex diminished in patients with tension-type headache compared with the other groups. Our findings indicate reduced excitability of the brain stem interneurons in patients with tension-type headache.
BACKGROUND Knobloch syndrome is a rare, autosomal recessive, developmental disorder characterized by stereotyped ocular abnormalities with or without occipital skull deformities (encephalocele, bone defects, cutis aplasia). Although there is clear heterogeneity in clinical presentation, central nervous system malformations, aside from the characteristic encephalocele, have not typically been considered a component of the disease phenotype. METHODS Four patients originally presented for genetic evaluation of symptomatic structural brain malformations. Whole-genome genotyping, whole-exome sequencing, and confirmatory Sanger sequencing were performed. Using immunohistochemical analysis, we investigated the protein expression pattern of COL18A1 in the mid-fetal and adult human cerebral cortex and then analyzed the spatial and temporal changes in the expression pattern of COL18A1 during human cortical development using the Human Brain Transcriptome database. RESULTS We identified two novel homozygous deleterious frame-shift mutations in the COL18A1 gene. Upon further investigation of these patients and their families, we found that many exhibited certain characteristics of Knobloch syndrome, including pronounced ocular defects. Our data strongly support an important role for COL18A1 in brain development and this report contributes to an enhanced characterization of the brain malformations that can result from deficiencies of collagen XVIII. CONCLUSIONS This case series highlights the diagnostic power and clinical utility of whole-exome sequencing technology – allowing clinicians and physician scientists to better understand the pathophysiology and presentations of rare diseases. We suggest that patients who are clinically diagnosed with Knobloch syndrome and/or found to have COL18A1 mutations via genetic screening should be investigated for potential structural brain abnormalities even in the absence of encephaloceles.
Patient: Male, 11Final Diagnosis: Haberland syndromeSymptoms: SeizureMedication: —Clinical Procedure: Medical treatmentSpecialty: NeurosurgeryObjective:Rare diseaseBackground:Encephalocraniocutaneous lipomatosis (ECCL) was first announced as a new type of ectomesodermal dysgenesis in 1970 by Haberland and Perou. ECCL was first described in 1970, and approximately 60 cases have been reported since then. The classic triad of ECCL are skin, ocular, and central nervous system involvement, including conditions such as unilateral porencephalic cyst, ipsilateral lipomatous hamartoma of the scalp-eyelids-eye globe, cortical atrophy, cranial asymmetry, developmental delay, seizures, mental retardation, and spasticity of the contralateral limbs. The dermatological hallmark is a hairless fatty tissue nevus of the scalp called nevus psiloliparus.Case Report:An 11-year-old right-handed boy, born at full term, was referred to our clinic. His family had no consanguinity or history of neurocutaneous disease. The patient’s physical examination revealed a large hairless lesion on the right frontoparietal scalp called nevus psiloliparus. Beginning from the birth, a dermolipoma (an uncommon benign tumor) was reported to have occurred on the conjunctiva, mostly ipsilateral in his right eye and present on the ipsilateral side of the neurological abnormalities shown on magnetic resonance imaging and computed tomography. The patient had muscle weakness in left upper and lower extremities. He had a mild form of mental retardation.Conclusions:There is no specific treatment for ECCL. Management of ECCL is usually symptomatic. Surgical correction of a cutaneous lesion can be performed for cosmetic improvement. An early diagnosis of ECCL allows for early symptom treatment and improved patient quality of life.
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