New NBIA subtype: genetic, clinical, pathologic, and radiographic features of MPAN

OBJECTIVE

To assess the frequency of mutations in C19orf12 in the greater neurodegeneration with brain iron accumulation (NBIA) population and further characterize the associated phenotype.

METHODS

Samples from 161 individuals with idiopathic NBIA were screened, and C19orf12 mutations were identified in 23 subjects. Direct examinations were completed on 8 of these individuals, and medical records were reviewed on all 23. Histochemical and immunohistochemical studies were performed on brain tissue from one deceased subject.

RESULTS

A variety of mutations were detected in this cohort, in addition to the Eastern European founder mutation described previously. The characteristic clinical features of mitochondrial membrane protein-associated neurodegeneration (MPAN) across all age groups include cognitive decline progressing to dementia, prominent neuropsychiatric abnormalities, and a motor neuronopathy. A distinctive pattern of brain iron accumulation is universal. Neuropathologic studies revealed neuronal loss, widespread iron deposits, and eosinophilic spheroidal structures in the basal ganglia. Lewy neurites were present in the globus pallidus, and Lewy bodies and neurites were widespread in other areas of the corpus striatum and midbrain structures.

CONCLUSIONS

MPAN is caused by mutations in C19orf12 leading to NBIA and prominent, widespread Lewy body pathology. The clinical phenotype is recognizable and distinctive, and joins pantothenate kinase-associated neurodegeneration and PLA2G6-associated neurodegeneration as one of the major forms of NBIA.

Zonisamide ameliorates symptoms of secondary paroxysmal dystonia

A number of medications have been used with varying success to treat the symptoms of generalized, focal, and paroxysmal dyskinesias; these agents include anticonvulsant, benzodiazepine, neuroleptic, dopaminergic, dopamine antagonist, and carbonic anhydrase inhibitor types. The carbonic anhydrase inhibitor drug group is best represented by acetazolamide, which has been widely applied in the treatment of paroxysmal dyskinesias. Zonisamide, which has several putative pharmacologic mechanisms of action, is a member of the carbonic anhydrase inhibitor drug group. Zonisamide was chosen for treatment of secondary paroxysmal dystonia in a patient with pyruvate dehydrogenase deficiency (case 1) and in two patients with neonatal hemochromatosis and family history of neonatal hemochromatosis (cases 2 and 3). Although zonisamide ameliorated the symptoms of secondary paroxysmal dystonia in these three patients, the precise biochemical mechanism remains unclear, and further studies are needed to substantiate and explain this finding.

Ocular findings in Gillespie-like syndrome: association with a new PAX6 mutation

BACKGROUND

Gillespie syndrome is a rare variant form of aniridia, characterized by mental retardation, nonprogressive cerebellar ataxia, and iris hypoplasia. Unlike the more common dominant and sporadic forms of aniridia, there have been no associated PAX6 mutations or Wilms' tumor reported in Gillespie syndrome patients. Ocular findings in 21 cases published since Gillespie's initial description in 1965 include iris and foveal hypoplasia, nystagmus, and small optic discs with pigmentary retinopathy.

CASE REPORT

We herein report a case of atypical Gillespie syndrome associated with bilateral ptosis, exotropia, corectopia, iris hypoplasia, anterior capsular lens opacities, foveal hypoplasia, retinal vascular tortuosity, and retinal hypopigmentation. Neurologic evaluation revealed a mild hand tremor and learning disability, but no ataxia or cerebellar abnormalities on neuroimaging. Sequencing studies revealed a substitution in intron 2 of the PAX6 gene (IVS2 + 2T > A). To our knowledge, this is the first mutation of PAX6 gene reported in association with a Gillespie-like syndrome.

Stereotactic pallidotomy in a child with Hallervorden-Spatz disease. Case report

The authors present a case of Hallervorden-Spatz disease (HSD) in a 10-year-old boy treated with stereotactic pallidotomy for control of severe dystonia. Hallervorden-Spatz disease is a rare type of neuraxonal dystrophy that can be familial or sporadic. This is the first case of HSD reported in the literature in which a pallidotomy was performed. The patient had progressively worsening dystonias and spasms that prevented useful function of his entire right side and eventually threatened his respiratory ability. Pre- and postoperative magnetic resonance images are presented along with electrophysiological recordings made in the globus pallidus at the time of surgery. Functional improvement in the use of the patient's limbs and relief from the painful dystonia were observed. Stereotactic pallidotomy should be considered as a potential treatment in the management of HSD.

Posttraumatic childhood lumbosacral plexus neuropathy

A 13-month-old male received crush injury to the abdomen resulting in paraparesis due to lumbosacral plexus neuropathy. The child was monitored with serial clinical examinations and electromyography/nerve conduction studies. He had complete clinical recovery. Lumbosacral plexus neuropathy is unusual in childhood and has not been previously reported as a result of abdominal trauma. This patient is presented with details of the clinical course, electrodiagnostic studies, discussion, and literature review.

Anterior fontanel herniation in group B streptococcus meningitis in newborns

Brain herniation at any site is a rare complication of neonatal meningitis. Two cases of anterior fontanel herniation, associated with group B beta-hemolytic streptococcus meningitis are reported. This finding is a poor prognostic sign.

Perioperative spinal canal narrowing in patients with Down's syndrome

Two patients with Down's syndrome undergoing intracardiac operations had segmental and generalized myoclonic movements postoperatively and eventual brain death. Electroencephalography in 1 patient showed no seizure despite the presence of the myoclonic movements. Computed tomographic scan showed possible cerebellar hemorrhage. Ultrasound showed cerebral edema when the pupils became fixed and dilated. Because known postoperative neurologic complications could not fully explain the clinical course, and the myoclonic movements suggested spinal origin, we considered the possibility of atlantoaxial instability causing spinal cord damage related to perioperative head and neck positioning. Postmortem study on the second patient revealed 50% reduction of the spinal canal with hyperextension and 90-degree external rotation of the head and neck. In contrast, similar maneuvers in 3 infants without Down's syndrome resulted in only mild spinal canal narrowing. Although the myoclonic movements could be explained by spinal cord compression at the atlantoaxial level, the explanation for the eventual brain death is unclear. However, kinking of the vertebral arteries related to the positioning could have caused cerebellar ischemia, hemorrhage, and increased intracranial pressure. We believe that attention to the problem might bring further answers in the future.

Phenacemide therapy of complex partial epilepsy in children: determination of plasma drug concentrations

We used monotherapy with phenacemide to treat complex partial seizures in 13 children who were refractory to conventional antiepileptic drug therapy. Twelve patients responded with a reduction in seizure frequency, and 5 have been totally seizure free since the start of therapy. Phenacemide therapy was well tolerated with a minimum of untoward side effects and no evidence of irreversible drug toxicity. We developed a rapid and sensitive assay for the determination of plasma phenacemide concentrations by high performance liquid chromatography to monitor drug levels during therapy. Seizure control was achieved at plasma drug levels that ranged from 16 to 75 micrograms/ml. The median effective dose in our series was 52 micrograms/ml. The recurrence of seizures in three patients was, in each case, associated with trough plasma phenacemide levels below 50 micrograms/dl.

Late-infantile neuronal ceroid-lipofuscinosis. An ultrastructural study of lymphocyte inclusions

Ultrastructural study of peripheral blood from two patients with late-infantile neuronal ceroid-lipofuscinosis with curvilinear bodies, demonstrated in brain biopsies revealed curvilinear bodies in lymphocytes. These findings indicate that ultrastructural investigation of circulating lymphocytes may be useful in the diagnosis of late-infantile neuronal ceroid-lipofuscinosis and may circumvent the need for brain biopsy. Curvilinear bodies were also present in the lymphocytes of a neurologically normal younger female sibling of patient 1, who has had a single seizure, leading to speculation that she may be in the early stages of the same disease. This case suggests the possibility of early detection of this disorder and indicates the importance of screening lymphocytes of siblings of affected patients. Tubular cytoplasm inclusions were present in a high percentage of lymphocytes of the asymptomatic parents and a younger sibling of these patients.