Baló's concentric sclerosis and tumefactive demyelination: a shared immunopathogenesis?

Baló's concentric sclerosis (BCS) and tumefactive demyelination (TD) are considered atypical forms of multiple sclerosis (MS). Baló lesions are characterized by concentric rings corresponding to alternating bands of demyelination and relatively preserved myelin (Hu and Lucchinetti, 2009). Tumefactive lesions are pseudotumoural demyelinating lesions of >2 cm and may have an open ring-enhancing magnetic resonance imaging appearance (Hu and Lucchinetti, 2009; Lucchinetti et al., 2008; Altintas et al., 2012). We present a patient who developed limb weakness and focal seizures secondary to a lesion radiologically and histopathologically consistent with BCS who, six months later, developed a tumefactive demyelinating lesion. This is the first description of BCS and TD occurring in the same patient and is particularly notable because of the lack of any other more typical demyelinating lesions on the MRIs. The nature of BCS and TD in relation to more typical multiple sclerosis is discussed.

Alpers syndrome: the natural history of a case highlighting neuroimaging, neuropathology, and fat metabolism.

Mitochondrial diseases are increasingly being recognized as causes of encephalopathy and intractable epilepsy. There is no gold-standard test for diagnosing mitochondrial disease, and the current diagnosis relies on establishing a consistent pattern of evidence from clinical data, neuroimaging, tissue biopsy, and biochemical, genetic, and other investigations. Experience in the diagnosis and treatment of patients with certain forms of mitochondrial disease, such as Alpers syndrome, is largely gained from case reports or small case series. The authors describe a case of Alpers syndrome due to POLG1 mutations, including serial neuroimaging and pathological investigations, to illustrate two main points: (1) Unique characteristics evident on serial diffusion-weighted imaging can be a valuable indicator of Alpers syndrome; and (2) abnormal lipid metabolism can be present in Alpers syndrome, which may need to be considered when using a ketogenic diet.

Alpers syndrome with mutations in POLG: clinical and investigative features.

Alpers syndrome is a rare autosomal recessive hepatocerebral degenerative disorder. Seventeen patients with Alpers syndrome or polymerase-γ gene mutations were identified. Case records of 12 patients with Alpers syndrome and polymerase-γ mutations in both alleles were reviewed. All patients manifested developmental delay or regression, refractory epilepsy, and biochemical liver dysfunction. Liver failure occurred in three patients previously treated with valproate. Other signs included ataxia, visual disturbance, motor paresis, and tremor. Myoclonic and focal motor seizures were common, often manifesting as status epilepticus. Electroencephalograms demonstrated absent/slow posterior dominant rhythms. Interictal discharges were common, usually involving the occipital lobes. Rhythmic high-amplitude delta with (poly)spikes was evident in four patients. Magnetic resonance imaging showed migratory, cortical, and subcortical T(2) hyperintensities in four children most often affected the parietal and occipital lobes. Developmental regression and refractory focal motor or myoclonic seizures are consistent clinical features of Alpers syndrome with polymerase-γ mutations. Liver dysfunction constitutes a late manifestation. Migratory T(2)/fluid attenuated inversion recovery signal abnormalities involving metabolically active occipital and sensorimotor cortical regions comprise characteristic imaging findings. Interictal and ictal electroencephalogram patterns are more variable than previously reported. Three common polymerase-γ mutations, in patients of European descent, can assist with rapid diagnosis, circumventing the need for liver biopsy.

Schilder's disease: non-invasive diagnosis? :A case report and review.

Schilder's disease, or myelinoclastic diffuse sclerosis, is a rare disorder characterised by an inflammatory white matter plaque of demyelination. Clinical signs and symptoms might be atypical for early multiple sclerosis and at imaging the lesion is easily taken for a brain tumour. Regardless of the use of Poser's criteria for clinical diagnosis of Schilder's disease proposed in 1986, diagnostic difficulties are still present, as evidenced by the many reported cases in the English literature revised (Pubmed indexed, period 1998-2008). It clearly emerges that neuroradiological features, observable in additional magnetic resonance sequences are crucial, besides the consideration of Poser's criteria, in differentiating between demyelinating lesions and brain tumours. A 29-year-old female patient is presented, where a careful evaluation of both the clinical and radiological features, which might have been at a first glance misleadingly suggestive for a brain tumour, allowed non-invasive diagnosis of Schilder's disease.

Dysmorphic neurons in patients with temporal lobe epilepsy.

We studied morphologic characteristics of dysmorphic neurons in the hippocampus of seven patients with medically intractable TLE and compare histological, clinical, and imaging features with ten TLE patients with classical hippocampal sclerosis without abnormal cells. Such dysmorphic neurons were observed in the hilus of the dentate gyrus and were characterized by giant or misshapen cells with abnormal cytoskeletal structure and atypical dendritic processes that resembled the dysmorphic neurons from cortical dysplasias. Specimens with dysmorphic cells also contained other cytoarchitectural abnormalities including bilamination of the dentate granular cell layer (four out seven cases), and the presence of Cajal-Retzius cells in the dentate gyrus or Ammon's horn (five out seven cases). There were no statistically significant differences regarding the age at onset, duration of epilepsy, and hippocampal asymmetry ratio between patients with or without dysmorphic cells. Nevertheless, it is interesting to note that a higher proportion of patients with dysmorphic neurons continued to present auras after surgery, when compared with patients without those cells.

[Schilder's disease: two new cases and a review of the literature]. / Enfermedad de Schilder: dos nuevos casos y revisión de la bibliografía.

INTRODUCTION: Schilder's disease, or diffuse myelinoclastic sclerosis, is an infrequent disease that presents clinically as a pseudotumoural demyelinating lesion, which makes its diagnosis more complicated as it can be mistaken for a tumour or an abscess. CASE REPORTS: We examine the case of a male who was healthy up to the age of 8 years, when symptoms of a left hemiparesis appeared with a subacute onset and which were associated to symptoms of intracranial hypertension. A brain CAT scan showed a hypodense lesion in the right temporoparietal region, and the hypothesis of a tumoural lesion (astrocyte) was suggested. Treatment was started with dexamethasone and furosemide, and a complete regression of the symptoms and a considerable decrease in the cerebral lesion were observed. The second case is that of a female adolescent who, at the age of 11, developed a clinical picture of subacute onset of left hemiplegia. A brain CAT scan revealed hypodense lesions with ring-shaped contrast enhancement. In view of the histological diagnosis of an astrocyte, radiotherapy and corticotherapy are started. After two months' treatment, a sharp involution of the lesions was observed, which led to the acceptance of the diagnostic hypothesis of Schilder's disease. Both children presented recurrence of the lesions three years and nine months, in the first and second case respectively, after the first episode. Treatment with corticoid therapy was started and gave good clinical and radiological responses. CONCLUSIONS: In the presence of a neurological deficit with a subacute onset, associated to a brain image showing a 'tumoural' lesion containing an important amount of oedema and little mass effect, diagnoses other than that of a brain tumour must be taken into account. It thus becomes possible to avoid invasive forms of treatment, such as surgical resection, which entail a number of sequelae.

Intraoperative hippocampal electrocorticography to predict the extent of hippocampal resection in temporal lobe epilepsy surgery.

OBJECT: Among the variety of surgical procedures that are performed for the treatment of medically refractory mesial temporal lobe epilepsy (TLE), no consensus exists as to how much of the hippocampus should be removed. Whether all patients require a maximal hippocampal resection has not yet been determined. METHODS: At the University of Washington, all TLE operations are performed in a tailored fashion, guided by electrocorticography (ECoG). The amount of hippocampal resection is determined intraoperatively by the extent of interictal epileptiform abnormalities on ECoG recorded from that structure, resulting in a hippocampal resection that is individualized for each patient. Using this approach, the authors prospectively observed 140 consecutive patients who underwent surgery for mesial TLE with pathological diagnoses of either mesial temporal sclerosis with neuronal loss (MTS group) or mild gliosis without neuronal loss (non-MTS group) to determine whether the extent of hippocampal resection correlates with outcome when a tailored approach is used. Additionally, the authors analyzed whether the presence of residual interictal epileptiform activity on ECoG following mesial temporal resection predicts poorer seizure control. With at least 18 months of clinical follow up, 67% of the 140 patients were seizure free or had only a single postoperative seizure. There was no correlation between the size of the hippocampal resection and seizure control in the group as a whole or when stratified by pathological subtype. Using an intraoperatively tailored strategy, individuals with a larger hippocampal resection (> 2.5 cm) were not more likely to have seizure-free outcomes than patients with smaller resections (p = 0.9). Additionally, both MTS and non-MTS patients, in whom postoperative ECoG detected residual epileptiform hippocampal (but not cortical or parahippocampal) interictal activity following surgical resection, had significantly worse seizure outcomes (p = 0.01 in the MTS group; p = 0.002 in the non-MTS group). CONCLUSIONS: Intraoperative hippocampal ECoG can predict how much hippocampus should be removed to maximize seizure-free outcome, allowing for sparing of possibly functionally important hippocampus.

[Connatal type of Pelizaeus-Merzbacher disease: a case report].

Pelizaeus-Merzbacher disease (PMD) is a hereditary disorder with myelin dysplasia in the central nervous system. The connatal type is a more severe form compared to the classical type and shows developmental arrest or deterioration, nystagmus, spasticity, and/or convulsions in the neonatal period. A 1 1/4-year-old Japanese boy diagnosed as connatal type PMD is reported here. Soon after his birth, he demonstrated horizontal and rotatory nystagmus and opisthotonic posture. At the age of 10 months, he had difficulty in feeding. At the age of 1 year, he presented more severe opisthotonic posture and frequent vomiting. He showed deterioration in gross motor development. His chromosome analysis showed a normal male karyotype. Electroencephalogram did not show a sleep spindle. Auditory evoked brainstem responses (ABR) showed only wave I on both sides. Visual evoked potentials (VEP) showed prolongation of latencies. These results were compatible with PMD. Nuclear magnetic resonance imaging (MRI) demonstrated in the white matter of cerebrum and brainstem no high intensities on T1-weighted images and diffuse high intensities on T2-weighted images. Such absence of myelination including the brainstem was characteristic to the connatal type PMD. The diffuse disturbance of myelination appeared to correlate with the severity of clinical symptoms.

Leukodystrophy in patients with ovarian dysgenesis.

We describe clinical, biochemical, pathological, and spectroscopic findings in 4 women, aged 15 to 29 years, from three unrelated families who had a unique combination of a central nervous system white matter disease and primary ovarian failure. All had normal initial development but 3 had borderline low IQ and academic difficulties in primary school. Puberty did not develop in 2 patients and was arrested in a third patient. The fourth patient had premature ovarian failure at the age of 13 years. Head magnetic resonance imaging showed diffuse white matter disease, with frontal cortical atrophy in the most clinically advanced patient. All patients had normal karyotype and normal findings on extensive evaluations for known leukodystrophies, for other metabolic diseases, and for causes of ovarian failure. Proton magnetic resonance spectroscopic imaging showed reduction of choline-containing compounds in the affected white matter in all patients and reduction of N-acetylaspartate in the unaffected frontal white matter of 2 patients. All patients had evidence of primary gonadal insufficiency with a normal hypothalamic-hypophyseal axis. Pathological analysis showed streak ovaries in 1 patient and signs of hypomyelination, and gliosis on brain biopsy in another patient. In conclusion, we present a novel group of patients who have in common leukodystrophy, primary ovarian dysfunction, and magnetic resonance spectroscopic abnormalities.

Clinical and pathological features of an autosomal dominant, adult-onset leukodystrophy simulating chronic progressive multiple sclerosis.

OBJECTIVE: To study the clinical and pathological features of a kindred with an adult-onset autosomal dominant leukodystrophy. PATIENTS: Five symptomatic and nine asymptomatic at-risk members of the kindred. INTERVENTIONS: Subjects underwent detailed histories and general and neurologic examinations. Further evaluation included electroencephalography, evoked potentials, electromyography, autonomic testing, and analysis of serum, urine, and cerebrospinal fluid. One patient underwent sural nerve biopsy and analysis. Another, previously studied patient, underwent a limited autopsy. RESULTS: Cerebellar and pyramidal dysfunction began in the fourth and fifth decades of life; subtle autonomic symptoms were often present years earlier. Frontal lobe dysfunction and abnormalities of the central visual pathways were mild and of late onset. Sensorineural hearing loss was common. The peripheral nervous system was spared. Autopsy results of one patient revealed severe degeneration of the white matter at all levels of the neuraxis, but most prominent in the frontoparietal and cerebellar regions, with sparing of the subcortical U fibers. Histological and ultrastructural examinations failed to show evidence of a specific pathogenetic mechanism or etiology. CONCLUSION: This disorder seems to be a distinct type of hereditary leukodystrophy, but its exact nature remains unknown.

Glial biology and disorders.

Much work has been devoted this year to the localization and mode of expression of growth factors and cytokines. Although it is not possible to extrapolate directly from in vitro to in vivo conditions, the plasticity of glial cells seems to be very influenced by growth factors. Astrocytes in vivo do not express many growth factors during normal conditions, but a pathologic event can lift these restrictions. Cytokines and their receptors have been localized on neuronal or glial cell types. The programmed cell death, well identified in neurons, seems to occur also in oligodendrocytes and may be influenced by survival factors. In the adult brain, glial progenitors are present and may be a potential source to generate myelinating oligodendrocytes for myelin repair. In the peripheral nervous system, axonal-Schwann cell signaling may function in both directions during development. Some animal neurologic mutants are models for human diseases; one of them, the Trembler mouse, has effectively led to the genetic characterization of Charcot-Marie-Tooth disease type 1a. As for myelin destruction, the relationship between demyelination and inflammation is still not very clear.

Increased intracranial pressure in Alexander disease: a rare presentation of white-matter disease.

A patient with biopsy-proven Alexander disease presented with progressive head enlargement and clinical evidence of increased intracranial pressure. Lumbar puncture under sedation confirmed increased intracranial pressure with otherwise normal cerebrospinal fluid values. The association of megalencephaly, increased intracranial pressure and neuroimaging evidence of leukoencephalopathy should alert pediatric neurologists to the possibility of Alexander disease.

[Striatal involvement on MRI in adrenomyeloneuropathy].

Adrenomyeloneuropathy (AMN), a clinical variant of child adrenoleukodystrophy (ALD), is an adult-onset progressive disorder which presents spastic paraparesis with peripheral nerve involvement and affects mainly the pyramidal tracts from the brainstem to the spinal cord. We report a case of AMN in which serial MRI showed unusual development of areas of high signal in the right striatum. The patient was in good health until the age of 12, when he began to lose his hair. At age 25 he started to have progressive gait disturbance and erectile impotence. In his first admission to our hospital at age 33, he showed diffuse baldness. He was intelligent but childish. His cranial nerves were normal. Muscle strength was weak (3-4/5) in the lower extremities. Deep tendon reflexes were hyperactive in the lower extremities while normal in the upper extremities. Babinski signs were elicited bilaterally. Pinprick and vibratory sensation was impaired in the lower legs. Proprioceptive sensations were normal. Co-ordination was intact. There were urinary incontinence and impairment of erection with preserved libido and ejaculation. Routine laboratory data including hematological studies, serum chemistry and urinalysis were all normal except for mild hyperlipidemia. Serum cortisol response to ACTH was low and serum levels of very long chain fatty acids were increased. Nerve conduction studies were abnormal and consistent with peripheral polyneuropathy. A biopsy specimen of left sural nerve revealed a mild loss of myelinated fibers with thinning of the myelin. These findings and the clinical features confirmed the diagnosis of AMN. MRI in SE2000/40 scans at age 34 disclosed areas of high signal in the bilateral internal capsules.(ABSTRACT TRUNCATED AT 250 WORDS)

Psychosis following temporal lobe surgery: a report of six cases.

Six consecutive patients who had had temporal lobe surgery for epilepsy, and been referred for psychiatric assessment of psychotic symptoms, are reported. Their symptoms (a delusional depression, four schizophrenia-like illnesses, and a case of Capgras' syndrome) are discussed in relation to the possible role of their operations, all of which were on the right hemisphere.

Pelizaeus-Merzbacher disease: classical or connatal?

The clinical features and investigation results of 7 patients with Pelizaeus-Merzbacher disease (PMD) are described; one patient had a brain biopsy and two patients had an autopsy. This paper tries to differentiate the clinical features of the connatal and classical types of PMD. Transient stridor and nystagmus were early signs in both types of PMD. Our findings support the view that the more severe connatal form shows rapid neurological deterioration from an early age leading to death usually in the first decade. In younger patients in whom the evolution is still unclear, severe feeding problems and extrapyramidal features may suggest the connatal form. By contrast, in the classical form of PMD, cerebellar signs and cognitive deterioration are more prominent with a more slowly progressive course. Nuclear magnetic resonance imaging and brainstem auditory evoked potentials were very helpful in supporting the diagnosis of PMD either in a known affected family or in sporadic cases, but were not useful in distinguishing between the two types of PMD. Genetic counseling in this condition is difficult, particularly in the connatal form in which inheritance may be either X-linked or autosomal recessive.

Central motor and sensory conduction in adrenoleukomyeloneuropathy, cerebrotendinous xanthomatosis, HTLV-1-associated myelopathy and tabes dorsalis.

Central motor and sensory conduction was studied by percutaneous electrical stimulation of brain and spinal cord and by somatosensory evoked potential techniques respectively, in patients with adrenoleukomyeloneuropathy, cerebrotendinous xanthomatosis, human T-cell lymphotropic virus-1-associated myelopathy and tabes dorsalis. The results were all consistent with clinical and neuropathological findings in these disorders. Conductions in the corticospinal tract and posterior column could be evaluated separately with these two techniques. Percutaneous electrical stimulation technique would be useful for investigating conduction in the corticospinal tract in patients with spinal cord disorders.

Auditory brainstem response and audiologic findings in adrenoleukodystrophy: its variant and carrier.

Auditory brain stem response, auditory sensitivity, speech discrimination function, acoustic reflex threshold, and reflex decay were studied in seven children with adrenoleukodystrophy (ALD), nine adults with adrenomyeloneuropathy (AMN), one child with neonatal ALD, and two carriers of ALD. Significant auditory dysfunctions were found in only two patients; a retrocochlear type auditory disorder in one child with ALD, and a profound deafness in a child with neonatal ALD. None of the patients showed significant abnormality in acoustic reflex threshold and reflex decay except for one patient with ALD who showed a slightly elevated reflex threshold. All but two ALD patients showed significantly prolonged wave latencies and interwave intervals. The latency values revealed the highest incidence of abnormality in the I to III interval; this was followed by the III to V interval, then by wave I. Significantly, one child with asymptomatic ALD and both heterozygous female relatives showed abnormal ABRs, demonstrating the high sensitivity of ABR in detection of the existence of pathophysiological condition in subclinical or presymptomatic ALD.

Brain-stem auditory evoked potentials in children with brain-stem or cerebellar dysfunction.

Brain-stem auditory evoked potentials (BAEPs) were recorded in 23 children who had signs of brain-stem or cerebellar dysfunction. In patients with brain-stem gliomas, BAEPs were abnormal in all except one, in whom involvement of the brain-stem auditory pathway was limited to the midbrain tectum. The BAEPs were normal in neuronal ceroid lipofuscinosis, but abnormal bilaterally in inheritable leukoencephalopathies. All patients with Leigh's encephalopathy had BAEP abnormalities; in two, abnormalities occurred before the appearance of lesions on computed tomographic scan. Patients with Friedreich's ataxia and giant axonal dystrophy had abnormal BAEPs, but the test was normal in a child with similar neurologic findings with vitamin E deficiency. Patients with diffuse metabolic encephalopathies had variable findings. Thus, BAEP abnormalities are nonspecific for various disease processes but are frequently seen in neoplastic and neurodegenerative diseases, with primary white matter or extensive brain-stem involvement.

Early auditory evoked potentials: developmental aspects and validity in neuropaediatric and audiologic disorders.

Auditory evoked potentials and in this context especially five waves in the first 10 ms (early auditory evoked potentials = EAEP) are a diagnostic aid in topodiagnosis of posterior fossa diseases. This is due to waves I to V which arise along the acoustic nerve and in brain stem structures such as medulla, pons and mid-brain. Besides an indication about the site of a lesion in the posterior fossa, wave V allows an objective threshold determination. The present results were gained in normal children aged 1-3 years and in children with neuropaediatric and audiologic disorders.