Artery occlusion independently predicts unfavorable outcome in cervical artery dissection

OBJECTIVE

To assess the impact of dissected artery occlusion (DAO) on functional outcome and complications in patients with cervical artery dissection (CeAD).

METHODS

We analyzed combined individual patient data from 3 multicenter cohorts of consecutive patients with CeAD (the Cervical Artery Dissection and Ischemic Stroke Patients [CADISP]-Plus consortium dataset). Patients with data on DAO and functional outcome were included. We compared patients with DAO to those without DAO. Primary outcome was favorable functional outcome (i.e., modified Rankin Scale [mRS] score 0-1) measured 3-6 months from baseline. Secondary outcomes included delayed cerebral ischemia, major hemorrhage, recurrent CeAD, and death. We performed univariate and multivariable binary logistic regression analyses and calculated odds ratios (OR) with 95% confidence intervals (CI), with adjustment for potential confounders.

RESULTS

Of 2,148 patients (median age 45 years [interquartile range (IQR) 38-52], 43.6% women), 728 (33.9%) had DAO. Patients with DAO more frequently presented with cerebral ischemia (84.6% vs 58.5%, p < 0.001). Patients with DAO were less likely to have favorable outcome when compared to patients without DAO (mRS 0-1: 59.6% vs 80.1%, p _unadjusted < 0.001). After adjustment for age, sex, and initial stroke severity, DAO was independently associated with less favorable outcome (mRS 0-1: OR 0.65, CI 0.50-0.84, p = 0.001). Delayed cerebral ischemia occurred more frequently in patients with DAO than in patients without DAO (4.5% vs 2.9%, p = 0.059).

CONCLUSION

DAO independently predicts less favorable functional outcome in patients with CeAD. Further research on vessel patency, collateral status and effects of revascularization therapies particularly in patients with DAO is warranted.

Genetic Imbalance Is Associated With Functional Outcome After Ischemic Stroke

Background and Purpose- We sought to explore the effect of genetic imbalance on functional outcome after ischemic stroke (IS). Methods- Copy number variation was identified in high-density single-nucleotide polymorphism microarray data of IS patients from the CADISP (Cervical Artery Dissection and Ischemic Stroke Patients) and SiGN (Stroke Genetics Network)/GISCOME (Genetics of Ischaemic Stroke Functional Outcome) networks. Genetic imbalance, defined as total number of protein-coding genes affected by copy number variations in an individual, was compared between patients with favorable (modified Rankin Scale score of 0-2) and unfavorable (modified Rankin Scale score of ≥3) outcome after 3 months. Subgroup analyses were confined to patients with imbalance affecting ohnologs-a class of dose-sensitive genes, or to those with imbalance not affecting ohnologs. The association of imbalance with outcome was analyzed by logistic regression analysis, adjusted for age, sex, stroke subtype, stroke severity, and ancestry. Results- The study sample comprised 816 CADISP patients (age 44.2±10.3 years) and 2498 SiGN/GISCOME patients (age 67.7±14.2 years). Outcome was unfavorable in 122 CADISP and 889 SiGN/GISCOME patients. Multivariate logistic regression analysis revealed that increased genetic imbalance was associated with less favorable outcome in both samples (CADISP: P=0.0007; odds ratio=0.89; 95% CI, 0.82-0.95 and SiGN/GISCOME: P=0.0036; odds ratio=0.94; 95% CI, 0.91-0.98). The association was independent of age, sex, stroke severity on admission, stroke subtype, and ancestry. On subgroup analysis, imbalance affecting ohnologs was associated with outcome (CADISP: odds ratio=0.88; 95% CI, 0.80-0.95 and SiGN/GISCOME: odds ratio=0.93; 95% CI, 0.89-0.98) whereas imbalance without ohnologs lacked such an association. Conclusions- Increased genetic imbalance was associated with poorer functional outcome after IS in both study populations. Subgroup analysis revealed that this association was driven by presence of ohnologs in the respective copy number variations, suggesting a causal role of the deleterious effects of genetic imbalance.

Cervical artery dissection in patients ≥60 years

Objective:

In a cohort of patients diagnosed with cervical artery dissection (CeAD), to determine the proportion of patients aged ≥60 years and compare the frequency of characteristics (presenting symptoms, risk factors, and outcome) in patients aged <60 vs ≥60 years.

Methods:

We combined data from 3 large cohorts of consecutive patients diagnosed with CeAD (i.e., Cervical Artery Dissection and Ischemic Stroke Patients–Plus consortium). We dichotomized cases into 2 groups, age ≥60 and <60 years, and compared clinical characteristics, risk factors, vascular features, and 3-month outcome between the groups. First, we performed a combined analysis of pooled individual patient data. Secondary analyses were done within each cohort and across cohorts. Crude and adjusted odds ratios (OR [95% confidence interval]) were calculated.

Results:

Among 2,391 patients diagnosed with CeAD, we identified 177 patients (7.4%) aged ≥60 years. In this age group, cervical pain (ORadjusted 0.47 [0.33–0.66]), headache (ORadjusted 0.58 [0.42–0.79]), mechanical trigger events (ORadjusted 0.53 [0.36–0.77]), and migraine (ORadjusted 0.58 [0.39–0.85]) were less frequent than in younger patients. In turn, hypercholesterolemia (ORadjusted 1.52 [1.1–2.10]) and hypertension (ORadjusted 3.08 [2.25–4.22]) were more frequent in older patients. Key differences between age groups were confirmed in secondary analyses. In multivariable, adjusted analyses, favorable outcome (i.e., modified Rankin Scale score 0–2) was less frequent in the older age group (ORadjusted 0.45 [0.25, 0.83]).

Conclusion:

In our study population of patients diagnosed with CeAD, 1 in 14 was aged ≥60 years. In these patients, pain and mechanical triggers might be missing, rendering the diagnosis more challenging and increasing the risk of missed CeAD diagnosis in older patients.

Epidemiology, pathophysiology, diagnosis, and management of intracranial artery dissection

Spontaneous intracranial artery dissection is an uncommon and probably underdiagnosed cause of stroke that is defined by the occurrence of a haematoma in the wall of an intracranial artery. Patients can present with headache, ischaemic stroke, subarachnoid haemorrhage, or symptoms associated with mass effect, mostly on the brainstem. Although intracranial artery dissection is less common than cervical artery dissection in adults of European ethnic origin, intracranial artery dissection is reportedly more common in children and in Asian populations. Risk factors and mechanisms are poorly understood, and diagnosis is challenging because characteristic imaging features can be difficult to detect in view of the small size of intracranial arteries. Therefore, multimodal follow-up imaging is often needed to confirm the diagnosis. Treatment of intracranial artery dissections is empirical in the absence of data from randomised controlled trials. Most patients with subarachnoid haemorrhage undergo surgical or endovascular treatment to prevent rebleeding, whereas patients with intracranial artery dissection and cerebral ischaemia are treated with antithrombotics. Prognosis seems worse in patients with subarachnoid haemorrhage than in those without.

Distal myopathy with upper limb predominance caused by filamin C haploinsufficiency

OBJECTIVE

In this study, we investigated the detailed clinical findings and underlying genetic defect in 3 presumably related Bulgarian families displaying dominantly transmitted adult onset distal myopathy with upper limb predominance.

METHODS

We performed neurologic, electrophysiologic, radiologic, and histopathologic analyses of 13 patients and 13 at-risk but asymptomatic individuals from 3 generations. Genome-wide parametric linkage analysis was followed by bidirectional sequencing of the filamin C (FLNC) gene. We characterized the identified nonsense mutation at cDNA and protein level.

RESULTS

Based on clinical findings, no known myopathy subtype was implicated in our distal myopathy patients. Light microscopic analysis of affected muscle tissue showed no specific hallmarks; however, the electron microscopy revealed changes compatible with myofibrillar myopathy. Linkage studies delineated a 9.76 Mb region on chromosome 7q22.1-q35 containing filamin C (FLNC), a gene previously associated with myofibrillar myopathy. Mutation analysis revealed a novel c.5160delC frameshift deletion in all patients of the 3 families. The mutation results in a premature stop codon (p.Phe1720LeufsX63) that triggers nonsense-mediated mRNA decay. FLNC transcript levels were reduced in muscle and lymphoblast cells from affected subjects and partial loss of FLNC in muscle tissue was confirmed by protein analysis.

CONCLUSIONS

The FLNC mutation that we identified is distinct in terms of the associated phenotype, muscle morphology, and underlying molecular mechanism, thus extending the currently recognized clinical and genetic spectrum of filaminopathies. We conclude that filamin C is a dosage-sensitive gene and that FLNC haploinsufficiency can cause a specific type of myopathy in humans.

Stereotactic radiosurgery for convexity meningiomas

OBJECT

Meningiomas of the cerebral convexity are often surgically curable because both the mass and involved dura mater can be removed. Stereotactic radiosurgery has become an important primary or adjuvant treatment for patients with intracranial meningiomas. The authors evaluated clinical and imaging outcomes in patients with convexity meningiomas after radiosurgery.

METHODS

The patient cohort consisted of 125 patients with convexity meningiomas managed using radiosurgery at some point during an 18-year period. The patient series included 76 women, 55 patients who had undergone prior resection, and 6 patients with neurofibromatosis Type 2. Tumors were located in frontal (80 patients), parietal (24 patients), temporal (12 patients), and occipital (9 patients) areas. The WHO tumor grades in patients with prior resections were Grade I in 34 patients, Grade II in 15 patients, and Grade III in 6 patients. Seventy patients underwent primary radiosurgery and therefore had no prior histological tumor diagnosis. The mean tumor volume was 7.6 ml. Radiosurgery was performed using the Leksell Gamma Knife with a mean tumor margin dose of 14.2 Gy.

RESULTS

Serial imaging was evaluated in 115 patients (92%). After primary radiosurgery, the tumor control rate was 92%. After adjuvant radiosurgery, the control rate was 97% for Grade I tumors. The actuarial tumor control rates at 3 and 5 years for the entire series were 86.1+/-3.8% and 71.6+/-8.6%, respectively. For patients with benign tumors (Grade I) and those without prior surgery, the actuarial tumor control rate was 95.3+/-2.3% and 85.8+/-9.3%, respectively. Delayed resection after radiosurgery was performed in 9 patients (7%) at an average of 35 months. No patient developed a subsequent radiation-induced tumor. The overall morbidity rate was 9.6%. Symptomatic peritumoral imaging changes compatible with edema or adverse radiation effects developed in 5%, at a mean of 8 months.

CONCLUSIONS

Stereotactic radiosurgery provides satisfactory control rates either after resection or as an alternate to resection, particularly for histologically benign meningiomas. Its role is most valuable for patients whose tumors affect critical neurological regions and who are poor candidates for resection. Both temporary and permanent morbidity are related to brain location and tumor volume.

Boost radiosurgery as a strategy after failure of initial management of pediatric primitive neuroectodermal tumors

OBJECT

The aim in this study was to determine the outcomes of boost stereotactic radiosurgery, specifically Gamma Knife surgery (GKS), for recurrent primitive neuroectodermal tumors (PNETs) in children in whom initial multimodality management had failed.

METHODS

The authors performed a retrospective analysis of 7 patients who underwent a total of 15 GKS procedures for locally recurrent or metastatic PNETs. Nine procedures were directed at the primary site, whereas 6 were directed at distant brain sites. All patients received multimodality therapy, including resection, fractionated radiotherapy, and chemotherapy. The mean interval from diagnosis to first stereotactic radiosurgery was 25.8 months (range 11-35 months). The mean tumor volume was 3.9 cm(3) (range 1.1-13.1 cm(3)), and an average marginal dose of 14.5 Gy (range 9-20 Gy) was administered.

RESULTS

Following salvage GKS, 2 patients had early disease progression (median survival of 5 months after GKS). Five patients had late disease progression (complete response in 3, partial response in 1, and stable disease in 1) and a median survival of 30 months after GKS. Four of the 5 patients who had late progression underwent repeat GKS for marginal recurrence. No adverse radiation effects were observed in these 7 patients.

CONCLUSIONS

The GKS modality was a well-tolerated and useful boost strategy in pediatric patients with PNET and a poor prognosis in whom initial multimodality management had failed. However, local or distant disease progression or diffuse leptomeningeal spread ultimately proved fatal to these patients.

Radiosurgery as definitive management of intracranial meningiomas

OBJECTIVE

Stereotactic radiosurgery has become an important primary or adjuvant minimally invasive management strategy for patients with intracranial meningiomas with the goals of long-term tumor growth prevention and maintenance of patient neurological function. We evaluated clinical and imaging outcomes of meningiomas stratified by histological tumor grade.

METHODS

The patient cohort consisted of 972 patients with 1045 intracranial meningiomas managed during an 18-year period. The series included 70% women, 49% of whom had undergone a previous resection and 5% of whom had received previous fractionated radiation therapy. Tumor locations included middle fossa (n = 351), posterior fossa (n = 307), convexity (n = 126), anterior fossa (n = 88), parasagittal region (n = 113), or other (n = 115).

RESULTS

The overall control rate for patients with benign meningiomas (World Health Organization Grade I) was 93%. In those without previous histological confirmation (n = 482), tumor control was 97%. However, for patients with World Health Organization Grade II and III tumors, tumor control was 50 and 17%, respectively. Delayed resection after radiosurgery was necessary in 51 patients (5%) at a mean of 35 months. After 10 years, Grade 1 tumors were controlled in 91% (n = 53); in those without histology, 95% (n = 22) were controlled. None of the patients developed a radiation-induced tumor. The overall morbidity rate was 7.7%. Symptomatic peritumoral imaging changes developed in 4% of the patients at a mean of 8 months.

CONCLUSION

Stereotactic radiosurgery provided high rates of tumor growth control or regression in patients with benign meningiomas with low risk. This study confirms the role of radiosurgery as an effective management choice for patients with small to medium-sized symptomatic, newly diagnosed or recurrent meningiomas of the brain.

Cardiac Involvement in Juvenile Ceroid Lipofuscinosis of the Spielmeyer-Vogt-Sjögren Type: Prospective Noninvasive Findings in Two Siblings

The results of prospective noninvasive cardiologic investigations, including echocardiography and Holter monitoring are described in 2 siblings with juvenile ceroid lipofuscinosis of the Spielmeyer-Vogt-Sjögren type. In the elder patient, echocardiography revealed ventricular hypertrophy with slowed ventricular relaxation. Holter monitoring showed not only bradycardia but also slow and fast ectopic atrial rhythms, sinus arrests and complex ventricular ectopic activity including ventricular tachycardia. In the younger patient the findings were less severe. These functional disturbances due to cardiac involvement, never reported before in this disease, are discussed.

Radiosurgery for chordomas and chondrosarcomas of the skull base

OBJECT

Chordomas and chondrosarcomas of the skull base are aggressive and locally destructive tumors with a high tendency for local progression despite treatment. The authors evaluated the effect of stereotactic radiosurgery (SRS) on local tumor control and survival.

METHODS

Twenty-eight patients with histologically confirmed chordomas (18) or chondrosarcomas (10) underwent Gamma Knife SRS either as primary or adjuvant treatment. Their ages ranged from 17 to 72 years (median 44 years). The most common presenting symptom was diplopia (26 patients, 93%). In two patients, SRS was the sole treatment. Twenty-six patients underwent between one and five additional surgical procedures. Two underwent an initial transsphenoidal biopsy. The average tumor volume was 9.8 cm3. The median dose to the tumor margin was 16 Gy.

RESULTS

No patient was lost to follow-up. Transient symptomatic adverse radiation effects developed in only one patient. The actuarial local tumor control for chondrosarcomas at 5 years was 80 +/- 10.1%. For chordomas both the actuarial tumor control and survival was 62.9 +/- 10.4%.

CONCLUSIONS

Stereotactic radiosurgery is an important option for skull base chordomas and chondrosarcomas either as primary or adjunctive treatment. Multimodal management appears crucial to improve tumor control in most patients.

Beta-amyloid precursor protein and early-onset Alzheimer's disease

One of the major pathological hallmarks of Alzheimer's disease is the deposition in the brain parenchyma and cerebral blood vessel walls of amyloid beta-protein, a 4kDa proteolytic product of the longer beta-amyloid precursor protein (APP). Six different single base mutations in the APP gene have been reported causing early-onset Alzheimer's disease (age at onset < or = 65 years) or related amyloidosis in a small number of families. Cell transfection experiments using wild-type and mutant APP cDNA indicated that APP mutations result in the production of more or longer, aggregation prone, A beta peptides.

Cranial nerve preservation and outcomes after stereotactic radiosurgery for jugular foramen schwannomas

OBJECTIVE

Jugular foramen region schwannomas are rare intracranial tumors that usually present with multiple lower cranial nerve deficits. For some patients, complete surgical resection is possible but may be associated with significant morbidity. Stereotactic radiosurgery is a minimally invasive alternative or adjunct to microsurgery for such tumors. We reviewed our clinical and imaging outcomes after patients underwent gamma knife radiosurgery for management of jugular foramen schwannomas.

METHODS

Thirty-four patients with 35 tumors (one patient had bilateral tumors) underwent radiosurgery between May 1990 and December 2005. Twenty-two patients had previous microsurgical resection and all patients experienced various cranial neuropathies. A median of six isocenters were used. Median marginal and maximum doses were 14 and 28 Gy, respectively.

RESULTS

None of the patients were lost to evaluation and the mean duration of follow-up was 83 months. Tumors regressed in 17 patients, remained stable in 16, and progressed in two. Five- and 10-year actuarial control rates were 97 and 94%, respectively. Preexisting cranial neuropathies improved in 20% and remained stable in 77% after radiosurgery. One patient worsened. The function of all previous intact nerves was preserved after radiosurgery.

CONCLUSION

Stereotactic radiosurgery proved to be a safe and effective management for newly diagnosed or residual jugular foramen schwannomas. Long-term tumor control rates and stability or improvement in cranial nerve function was confirmed.

STEREOTACTIC RADIOSURGERY FOR VESTIBULAR SCHWANNOMAS IN PATIENTS WITH NEUROFIBROMATOSIS TYPE 2

OBJECTIVE

Vestibular schwannomas present significant management challenges in patients with neurofibromatosis Type 2 (NF2). We evaluated the results of gamma knife radiosurgery for the management of these tumors, focusing on tumor response, hearing preservation, and other factors affecting outcomes.

METHODS

Stereotactic radiosurgery was performed to manage 74 schwannomas in 62 patients. Ipsilateral serviceable hearing was present in 35% of tumors before the procedure. The mean tumor volume was 5.7 cm3. The mean margin and maximum dose used were 14 and 27.5 Gy, respectively. Cox regression analyses were performed to identify factors affecting outcomes.

RESULTS

The median follow-up period was 53 months, and two patients were lost to follow-up. Actuarial local control rates at were 85, 81, and 81% at 5, 10, and 15 years, respectively. Tumor volume was significant as a predictor of local control. Since 1992, using current radiosurgery techniques (magnetic resonance imaging scan targeting and reduced margin dose to 14 Gy or less), the actuarial serviceable hearing preservation rate is 73% at 1 year, 59% at 2 years, and 48% at 5 years after radiosurgery. Facial neuropathy occurred in 8% of tumors, trigeminal neuropathy occurred in 4%, and vestibular dysfunction occurred in 4%. Radiation dose and tumor volume were predictive of development of new deficits. No radiosurgery-associated secondary tumors or atypical or malignant changes were noted.

CONCLUSION

Stereotactic radiosurgery is a safe and effective management modality for neurofibromatosis Type 2 vestibular schwannomas. Although results do not seem to be as good as for patients with sporadic unilateral tumors, gamma knife radiosurgery results seem favorable and indicate that radiosurgery should be strongly considered for primary tumor management in selected patients.

Radiosurgery for miscellaneous skull base tumors

Stereotactic radiosurgery has become an integral part of conventional and advanced skull base surgery. Despite the advances in skull base techniques, the goal of total resection of such tumors is often problematic and associated with significant risk to critical structures of the skull base, including those within the cavernous sinus, those in the petrous apex, and the jugular bulb. Aggressive resection of such tumors sometimes results in severe adverse neurological events, ranging from permanent extraocular movement deficits to hearing loss, facial weakness, and difficulties with vagal and glossopharyngeal function. Gamma Knife radiosurgery is a primary alternative option for these patients. It minimizes the risks of open surgical techniques and preserves existing cranial nerve function in most patients and achieves tumor growth arrest. Adjuvant radiosurgery is used for larger tumors after their initial partial resection. Gamma Knife radiosurgery becomes an adjuvant tool to provide longterm tumor growth control of a significantly reduced tumor volume.

Central nervous system metastases of pulmonary adenocarcinoma mimicking neurofibromatosis type 2

We report a case of a 51-year-old man presenting with rapidly progressive unilateral tinnitus, hearing loss and imbalance. Neuroimaging revealed bilateral VIIIth cranial nerve masses and multiple cerebral and spinal cord lesions that were interpreted as being acoustic schwannomas and multiple meningeomas. An initial tentative diagnosis of neurofibromatosis type 2 (NF2) was made. Both clinical and radiological evolution were atypical for NF2 and the initial diagnosis of NF2 was questioned. Additional technical investigations demonstrated a pulmonary adenocarcinoma. Postmortem examination confirmed that this patient had multiple central nervous system metastases of a primary pulmonary adenocarcinoma, presenting clinically and neuroradiologically as a probable neurofibromatosis type 2. Clinicians should be aware of the rare possibility of central nervous system metastases mimicking NF2.

Extracerebral biopsy in lysosomal and peroxisomal disorders. Ultrastructural findings

The lysosomal and peroxisomal disorders are characterized by specific storage affecting mainly the central nervous system with involvement of the peripheral nervous system and visceral organs. Most of these disorders can now be diagnosed by using biochemical and enzymatical assays and by molecular biology techniques, without the need for a brain biopsy used previously. Extraneural tissue biopsies have also been investigated at the ultrastructural level. The study of such tissues is still necessary when the enzymatic or biochemical defect remains unknown and when DNA studies are not informative. The choice of tissue is important. Skin and conjunctival biopsies are less traumatic and are cost-effective diagnostic tools allowing the examination of a great diversity of structures. Skeletal muscle and peripheral nerves are more frequently used for patients with a late-onset or slower course of disease. Rectal biopsy is helpful when neurons require examination in lysosomal diseases, whereas liver is more usually investigated than adrenal or testis in peroxisomal diseases. Bone marrow is most useful for Gaucher's disease while lymphocytes may be examined for all lysosomal disorders as a first diagnostic approach. Chorionic villi still have a diagnostic role in combination of electron microscopy with DNA studies in early pregnancies at-risk for neuronal ceroid lipofuscinosis. Cultured fibroblasts are less informative than other biopsy samples for the morphological evaluation of lysosomal and peroxisomal disorders.

Indications for resection and radiosurgery for brain metastases

PURPOSE OF REVIEW

This review is focused on indications for resection, stereotactic radiosurgery, and fractionated radiotherapy for patients with single or multiple brain metastases. Our purpose is to summarize the indications and effect of these management approaches.

RECENT FINDINGS

Brain metastases are a frequent challenge in patients with extracranial solid cancers. More than 40% of patients with cancer will develop metastases to the brain. While some patients present with large lesions and symptoms related to mass effect, many are diagnosed when asymptomatic tumors are found on screening studies. The main options for patients with brain metastases are whole brain radiation therapy, surgical resection, and stereotactic radiosurgery. Much information regarding outcomes, survival, management morbidity, and quality of life is available. Randomized, class III clinical trials demonstrate that multimodal therapy is important for both life quality and extended survival. A better understanding of the current therapeutic options should result in improvements in patient care.

SUMMARY

This is a review of the literature from May 2004 to June 2005 with special attention on publications related to effect on quality of life with different procedures and therapies.

Long-term survivors after gamma knife radiosurgery for brain metastases

BACKGROUND

Stereotactic radiosurgery, with or without whole-brain radiation therapy, has become a valued management choice for patients with brain metastases, although their median survival remains limited. In patients who receive successful extracranial cancer care, patients who have controlled intracranial disease are living longer. The authors evaluated all brain metastasis in patients who lived for > or = 4 years after radiosurgery to determine clinical and treatment patterns potentially responsible for their outcome.

METHODS

Six hundred seventy-seven patients with brain metastases underwent 781 radiosurgery procedures between 1988 and 2000. Data from the entire series were reviewed; and, if patients had > or = 4 years of survival, then they were evaluated for information on brain and extracranial treatment, symptoms, imaging responses, need for further care, and management morbidity. These long-term survivors were compared with a cohort who lived for < 3 months after radiosurgery (n = 100 patients).

RESULTS

Forty-four patients (6.5%) survived for > 4 years after radiosurgery (mean, 69 mos with 16 patients still alive). The mean age at radiosurgery was 53 years (maximum age, 72 yrs), and the median Karnofsky performance score (KPS) was 90. The lung (n = 15 patients), breast (n = 9 patients), kidney (n = 7 patients), and skin (melanoma; n = 6 patients) were the most frequent primary sites. Two or more organ sites outside the brain were involved in 18 patients (41%), the primary tumor plus lymph nodes were involved in 10 patients (23%), only the primary tumor was involved in 9 patients (20%), and only brain disease was involved in 7 patients (16%), indicating that extended survival was possible even in patients with multiorgan disease. Serial imaging of 133 tumors showed that 99 tumors were smaller (74%), 22 tumors were unchanged (17%), and 12 tumors were larger (9%). Four patients had a permanent neurologic deficit after brain tumor management, and six patients underwent a resection after radiosurgery. Compared with the patients who had limited survival (< 3 mos), long-term survivors had a higher initial KPS (P = 0.01), fewer brain metastases (P = 0.04), and less extracranial disease (P < 0.00005).

CONCLUSIONS

Although the expected survival of patients with brain metastases may be limited, selected patients with effective intracranial and extracranial care for malignant disease can have prolonged, good-quality survival. The extent of extracranial disease at the time of radiosurgery was predictive of outcome, but this does not necessarily mean that patients cannot live for years if treatment is effective.

POLG mutations in neurodegenerative disorders with ataxia but no muscle involvement

OBJECTIVE

To identify POLG mutations in patients with sensory ataxia and CNS features.

METHODS

The authors characterized clinical, laboratory, and molecular genetic features in eight patients from five European families. The authors conducted sequencing of coding exons of POLG, C10orf2 (Twinkle), and ANT1 and analyzed muscle mitochondrial DNA (mtDNA), including Southern blot analysis and long-range PCR.

RESULTS

Ataxia occurred in combination with various CNS features, including myoclonus, epilepsy, cognitive decline, nystagmus, dysarthria, thalamic and cerebellar white matter lesions on MRI, and neuronal loss in discrete gray nuclei on autopsy. Gastrointestinal dysmotility, weight loss, cardiomyopathy, and valproate-induced hepatotoxicity occurred less frequently. Two patients died without preceding signs of progressive external ophthalmoplegia. In muscle, typical findings of mitochondrial disease, such as ragged red fibers and Southern blot mtDNA abnormalities, were absent. POLG mutations were present in eight patients, including two isolated cases, and one Finnish and two unrelated Belgian families contained in total six patients. All POLG mutations were recessive, occurring in a homozygous state in seven patients and in a compound heterozygous state in one patient. The novel W748S mutation was identified in five patients from three unrelated families.

CONCLUSIONS

The clinical spectrum of recessive POLG mutations is expanded by sensory ataxic neuropathy, combined with variable features of involvement of CNS and other organs. Progressive external ophthalmoplegia, myopathy, ragged red fibers, and Southern blot abnormalities of muscle mitochondrial DNA also are not mandatory features associated with POLG mutations.

Gamma knife radiosurgery for trigeminal schwannomas

BACKGROUND

Trigeminal schwannomas are uncommon tumors that may be microsurgically removed in selected cases, albeit with significant risk for new neurological morbidity. We evaluated the role of stereotactic radiosurgery as an alternative for patients with newly diagnosed or residual trigeminal schwannomas.

METHODS

The records of 23 patients who underwent radiosurgery for trigeminal schwannoma were reviewed. The most frequent presenting symptoms were facial numbness (11 patients), diplopia (6 patients), and facial pain (3 patients). One patient presented with partial complex seizures as the first symptom. Twelve patients had undergone one or more prior resections. Eleven underwent radiosurgery on the basis of imaging diagnosis only. The mean tumor volume was 4.5 mL (range 0.46-11.2 cc). Radiosurgery was performed using a median marginal dose of 15 Gy (range, 13-20 Gy).

RESULTS

At a median imaging follow-up of 40 months (range, 12-146), 20 of 22 evaluable patients (91%) had tumor growth control (regression in 15 and no further tumor growth in 5). One 80-year-old patient died of unrelated cause 4 months after radiosurgery. Two patients with enlarged tumors were treated effectively with repeat radiosurgery. Twelve of 23 patients (52%) reported improvement and 9 (39%) had no change in their symptoms. Two patients noted new neurological complaints (transient facial weakness in 1 patient and worsening of the preradiosurgery facial numbness in another patient).

CONCLUSIONS

Radiosurgery is an effective minimally invasive management option for patients with residual or newly diagnosed trigeminal schwannomas.

SPTLC1 mutation in twin sisters with hereditary sensory neuropathy type I

Hereditary sensory neuropathy type I (HSN I) is an autosomal dominant ulceromutilating disorder of the peripheral nervous system characterized by progressive sensory loss. HSN I locus maps to chromosome 9q22.1-22.3 and is caused by mutations in the gene coding for serine palmitoyltransferase long-chain base subunit 1 (SPTLC1). A novel missense mutation in exon 13 of the SPTLC1 gene (c.1160G-->C; p.G387A) in twin sisters with a severe HSN I phenotype is reported.

Patient homozygous for a recessive POLG mutation presents with features of MERRF

Both dominant and recessive missense mutations were recently reported in the gene encoding the mitochondrial DNA polymerase gamma (POLG) in patients with progressive external ophthalmoplegia (PEO). The authors report on a patient homozygous for a recessive missense mutation in POLG who presented with a multisystem disorder without PEO. The most prominent features were myoclonus, seizure, and sensory ataxic neuropathy, so the clinical picture overlapped with the syndrome of myoclonus, epilepsy, and ragged red fibers (MERRF).

A prospective study of CSF markers in 250 patients with possible Creutzfeldt-Jakob disease

OBJECTIVE

To investigate various cerebrospinal fluid (CSF) markers that could assist in the clinical diagnosis of Creutzfeldt-Jakob disease (CJD).

METHODS

CSF samples were analysed for the presence of 14-3-3 protein, microtubule associated protein tau, and beta amyloid in 250 patients with possible CJD. Densitometric analysis was used to quantify the level of 14-3-3 in all patients.

RESULTS

Analysis of the clinical data showed that cerebellar signs or myoclonus combined with progressive dementia were the main features leading to a clinical suspicion of CJD. While 14-3-3 detection had a sensitivity of 100% and a specificity of 92%, tau determination using a threshold of 1300 pg/ml had a sensitivity of 87% and a specificity of 97%. If the protocol for the analysis of 14-3-3 was modified (using densitometric analysis) a higher specificity (97%) could be obtained, but with a lower sensitivity (96%). Maximum sensitivity, specificity, and positive predictive value were obtained with a combination of 14-3-3 and beta amyloid determinations. The concentrations of 14-3-3 and tau in the CSF were reduced in CJD patients with a long duration of disease (more than one year; p < 0.05). The concentrations of 14-3-3 or tau were lowest at the onset or at the end stage of the disease, while the beta amyloid concentration remained low throughout the course of the disease.

CONCLUSIONS

Both 14-3-3 and tau protein are sensitive and specific biomarkers for CJD. The combination of 14-3-3 and beta amyloid analysis resulted in the maximum sensitivity, specificity, and positive predictive value. When these biomarkers are used in the diagnosis of CJD, the phase of the disease in which the CSF sample was obtained should be taken into account. Disease duration, dependent on the PrP genotype, also has a significant influence on the level of 14-3-3 and tau in the CSF.

An unusual case of generalized oedema

We present the case of a 66-year-old woman with generalized oedema and pain in the four limbs. Physical examination revealed a diffuse, painful, partly pitting, oedema of forearms, hands, lower legs and feet. There were no signs of synovitis. Laboratory investigation was non relevant, except for mild eosinophilia, which normalized subsequently. Cardiac, nephrological and venous disturbances were excluded. More uncommon disorders, such as eosinophilic fasciitis, early stage of scleroderma and polymyositis were considered. MRI scanning of the right forearm revealed an increased signal intensity in the superficial muscle fibers and thickening of the fascia (figure 1). Subsequently a full thickness biopsy of the musculus flexor digitorum superficialis was performed, revealing an inflammatory infiltration of lymphocytes and eosinophils, localized in the fascia. There was no necrosis of muscle fibers. No signs of scleroderma were found. The biopsy confirmed the diagnosis of eosinophilic fasciitis. Clinical and MRI findings suggested an early stage of disease and the patient was treated with low-dose corticosteroids.

Recessive POLG mutations presenting with sensory and ataxic neuropathy in compound heterozygote patients with progressive external ophthalmoplegia

Autosomal recessive progressive external ophthalmoplegia is a mitochondrial disease characterized by accumulation of multiple large-scale deletions of mitochondrial DNA. We previously reported missense mutations in POLG, the gene encoding the mitochondrial DNA polymerase gamma in two nuclear families compatible with autosomal recessive progressive external ophthalmoplegia. Here, we report a novel POLG missense mutation (R627W) in a sporadic patient and we provide genetic support that all these POLG mutations are actually causal and recessive. The novel patient presented with sensory ataxic neuropathy and has the clinical triad of sensory ataxic neuropathy, dysarthria and ophthalmoparesis (SANDO). This is the first finding of a genetic cause of Sensory Ataxic Neuropathy, Dysarthria and Ophthalmoparesis and it implies that this disorder may actually be a variant of autosomal recessive progressive external ophthalmoplegia. Sensory neuropathy is the initial feature in Belgian compound heterozygote autosomal recessive progressive external ophthalmoplegia patients, all carrying the POLG A467T mutation, which occurs at a frequency of 0.6% in the Belgian population.

[Hereditary neuropathy with liability to pressure palsies: study of six Spanish families]

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant inherited demyelinating neuropathy typically characterized by recurrent episodes of acute painless peripheral nerve palsies often preceded by minor trauma or compression at entrapment sites. However, less classical phenotypes have been reported. A 1.5 Mb deletion in chromosome 17 p11.2 has been shown to be the genetic basis of the disease in the majority of HNPP patients. The few families without this deletion harbored a mutation in the PMP22 gene. We performed a clinical, neurophysiological and molecular genetic study of 6 Spanish HNPP families. Five families (22 individuals) showed the classical chromosome 17 p11.2 deletion and one family (3 individuals) had a novel 3'splice-site mutation in PMP22. Neurophysiological abnormalities were detected in all symptomatic (n=21) and asymptomatic (n=4) deletion or mutation carriers, even in childhood. In addition to the typical presentation we observed other phenotypes: recurrent focal short-term sensory symptoms, a progressive mononeuropathy, a Charcot-Marie-Tooth (CMT) disease-like chronic progressive polyneuropathy, a chronic sensory polyneuropathy and a chronic inflammatory demyelinating polyneuropathy. We report new or very rare phenotypesThese atypical clinical aspects and intrafamilial heterogeneity are present in families with the HNPP deletion as well as in the family with the PMP22 mutation. However, the CMT disease-like chronic polyneuropathy was more common in the PMP22 mutation family. Intrafamilial heterogeneity also seemed to be more pronounced in this kinship. Patients in this family had a mild chronic motor and sensory polyneuropathy neurophysiologically characterized by delayed distal latencies, reduced nerve conduction velocities (NCV) within the demyelinating range, mildly decreased amplitudes of motor and sensory evoked potentials and absence of conduction blocks. In contrast, patients with the common HNPP deletion, regardless of their phenotype, had a diffuse increase in distal motor latencies contrasting with moderately reduced motor NCVs, preserved sensory nerve action potentials, slowing of NCVs at the common entrapment sites and occasionally conduction blocks. In this study we confirm the clinical and molecular heterogeneity of HNPP, emphasizing the need for a mutation analysis of the PMP22 gene when the common 17p11.2 deletion is not found in clinically suspected HNPP patients. We conclude that the 3'splice-site mutation in PMP22 and the common HNPP deletion have largely the same functional consequences although some clinical and neurophysiological differences were observed.

Autosomal dominant adult neuronal ceroid lipofuscinosis: parkinsonism due to both striatal and nigral dysfunction

We describe a family with adult neuronal ceroid lipofuscinosis, with apparent autosomal dominant inheritance, observed in six affected individuals in three generations. Disease onset was usually in the fifth decade, but was earlier in the youngest generation. Early symptoms consisted of myoclonus in face and arms, epilepsy, auditory symptoms, cognitive decline, or depression. Parkinsonism occurred a few years after disease onset, with stooped posture, shuffling gait, bradykinesia, and mask face. Four subjects deteriorated to a state of severe handicap, with severe dementia, contractures, dysphagia, and dysarthria. Leg weakness evolved to flaccid paraparesis in two patients. Diagnosis was confirmed by brain biopsy in one patient and full autopsy in two patients. Abundant intraneuronal storage of autofluorescent material was found throughout the brain. Electron microscopy showed granular osmiophilic deposits and scarce fingerprint profiles. Striking loss of neurons in the substantia nigra pars compacta and reticulata was found. (123)I-IBZM Single photon emission computed tomography in two patients showed loss of postsynaptic D2 receptor binding in the striatum. We conclude that parkinsonism in ANCL is likely to be caused by both presynaptic nigral cell loss and postsynaptic striatal degeneration.

Neuropathology of some hereditary conditions affecting central and peripheral nervous system

Neuropathology plays a crucial role in the phenotypic individualization of hereditary disorders affecting the central and peripheral nervous system even if molecular genetics represents the most essential step in describing the genotypes. The neuropathological description of phenotypes and genotypes can be used for refining clinical skills and understanding many clinical, neurophysiological and neuroradiological features. It contributes to the diagnosis of such disorders. The use of immunohistochemical techniques in combination with molecular genetics improves also our knowledge of their pathogenesis and might participate to the future development of therapeutic strategies. We discuss new features of spino-cerebellar ataxia (SCA) type 7 and of a recently identified SCA17 in order to illustrate the significance of the neuronal intranuclear inclusions (NIIs) described in various CAG/polyglutamine repeat expansion diseases. In the field of the peripheral neuropathies we present data on a newly described autosomal recessive Charcot-Marie-Tooth disease (CMT4F) with mutations in the periaxin gene. We document a dysjunction between myelin loops and axolemma with disappearance of the septate-like junctions or transverse bands. The significance of this dysjunction is not yet elucidated. We hope to show by these examples that the combination of classical and new neuropathological methods is useful in the study of hereditary disorders of the nervous system.

Hereditary neuromuscular diseases

This article presents the actual classification of neuromuscular diseases based on present expansion of our knowledge and understanding due to genetic developments. It summarizes the genetic and clinical presentations of each disorder together with CT findings, which we studied in a large group of patients with neuromuscular diseases. The muscular dystrophies as the largest and most common group of hereditary muscle diseases will be highlighted by giving detailed information about the role of CT and MRI in the differential diagnosis. The radiological features of neuromuscular diseases are atrophy, hypertrophy, pseudohypertrophy and fatty infiltration of muscles on a selective basis. Although the patterns and distribution of involvement are characteristic in some of the diseases, the definition of the type of disease based on CT scan only is not always possible.

Cerebral amyloid angiopathy is a pathogenic lesion in Alzheimer's disease due to a novel presenilin 1 mutation

The dense-cored plaques are considered the pathogenic type of amyloid deposition in Alzheimer's disease brains because of their predominant association with dystrophic neurites. Nevertheless, in > 90% of cases of Alzheimer's disease amyloid is also deposited in cerebral blood vessel walls (congophilic amyloid angiopathy; CAA) but its role in Alzheimer's disease pathogenesis remains enigmatic. Here, we report a family (family GB) in which early-onset Alzheimer's disease was caused by a novel presenilin 1 mutation (L282V). This was unusually severe CAA reminiscent of the Flemish amyloid precursor protein (A692G) mutation we reported previously, which causes Alzheimer's disease and/or cerebral haemorrhages. In family GB, however, the disease presented as typical progressive Alzheimer's disease in the absence of strokes or stroke-like episodes. Similarly, neuroimaging studies and neuropathological examination favoured a degenerative over a vascular dementia. Interestingly, an immunohistochemical study revealed that, similar to causing dense-cored amyloid plaques, CAA also appeared capable of instigating a strong local dystrophic and inflammatory reaction. This was suggested by the observed neuronal loss, the presence of tau- and ubiquitin-positive neurites, micro- and astrogliosis, and complement activation. Together, these data suggest that, like the dense-cored neuritic plaques, CAA might represent a pathogenic lesion that contributes significantly to the progressive neurodegeneration that occurs in Alzheimer's disease.

Influence of the prion protein and the apolipoprotein E genotype on the Creutzfeldt-Jakob Disease phenotype

We investigated the risk associated with the codon 129 polymorphism in the prion protein gene (PRNP) and apolipoprotein E gene (APOE) isoforms for development of Creutzfeldt-Jakob disease (CJD) (n=126) and the possible influences on the disease pathology and its most important clinical characteristics. The PRNP M129V (PRNP129) polymorphism was determined using both DNA extracted from formalin fixed and paraffin embedded brain tissue (n=59) and leukocyte extracted DNA (n=67). In the latter group also the PRNP open reading frame and the APOE genotype were analysed and compared to a neurologically unaffected, age and sex matched control group (n=79). We found that methionine homozygosity of the PRNP129 increases the risk for developing CJD. PRNP129 also influenced the prion accumulation patterns in brain. The APOE 4 allele was an independent risk factor for developing CJD. We further observed a significant dose dependent APOE 4 effect on the number and type of amyloid-beta plaques in the brain of CJD patients.

CAG repeat expansion in the TATA box-binding protein gene causes autosomal dominant cerebellar ataxia

At least 13 loci responsible for autosomal dominant cerebellar ataxia (ADCA) have been identified. Spinocerebellar ataxia 1, 2, 3, 6 and 7 are caused by translated CAG repeat expansions. However, in France, >30% of ADCAs are not explained by the known genes. Recently, analysis of the TATA box-binding protein (TBP) gene, one of the transcription factors known to contain a CAG/CAA repeat, in patients with progressive cerebellar ataxia revealed one sporadic case with 63 repeats. We examined this gene in 162 index cases with ADCA. An expanded repeat with 46 repeat units was detected in a single index case from Belgium. In this family, two affected members and six unaffected, but at-risk, individuals carried expanded alleles. Interestingly, the expanded repeat was stable during transmission. The main clinical features in six patients were cerebellar ataxia, dementia and behavioural disturbances with onset in their fourth to sixth decade. The main neuropathological finding was severe neuronal loss and gliosis in the Purkinje cell layer. Immunohistochemical analysis showed neuronal intranuclear inclusions containing expanded polyglutamine, indicating that this disease shares several features with other polyglutamine diseases. This study demonstrates that CAG/CAA repeat expansion in the TBP gene causes ADCA with dementia and/or psychiatric manifestations.

Infantile demyelinating neuropathy associated with a de novo point mutation on Ser72 in PMP22 and basal lamina onion bulbs in skin biopsy

Codon 72 has been designated as a hot spot for distinct missense mutations in the peripheral myelin protein 22 (PMP22) gene. Ser72Leu substitution was associated with Dejerine-Sottas syndrome (DSS) in four patients and with congenital hypomyelination neuropathy (CHN) in one patient. Our objective was to report one other DSS patient with Ser72Leu substitution in PMP22 and to concurrently illustrate how less invasive procedures such as skin biopsy could provide a rapid and reliable alternative to conventional sural nerve biopsy for the characterization of histophenotypic features. A skin biopsy was carried out in a 2 4/12-year-old girl with muscle atrophy, hypotonia and weakness, as well as generalized areflexia and absent sensory and motor nerve responses. Standard electron microscope techniques were used. PMP22 was screened by automated direct nucleotide sequencing analysis. Morphological examination revealed basal lamina onion bulbs surrounding a de- or hypomyelinated axon in all nerve bundles. Mutation analysis demonstrated a missense point mutation in codon 72 of the PMP22 gene leading to a Ser72Leu substitution. Further genotype-phenotype correlations will have to determine whether morphologically distinct phenotypes can be correlated with specific mutations. For this purpose, cutaneous nerve bundles could serve as an alternative tool to help identify and classify subtypes in this heterogeneous syndrome.

Identification of a putative sordarin binding site in Candida albicans elongation factor 2 by photoaffinity labeling

Candida albicans EF-2 binds sordarin to a single class of binding sites with K(d) = 1.26 microm. Equimolar mixtures of EF-2 and ribosomes, in the presence of a non-hydrolyzable GTP analog, reveal two classes of high affinity sordarin binding sites with K(d) = 0.7 and 41.5 nm, probably due to the existence of two ribosome populations. Photoaffinity labeling of C. albicans EF-2 in the absence of ribosomes has been performed with [(14)C]GM258383, a photoactivatable sordarin derivative. Labeling is saturable and can be considered specific, because it can be prevented with another sordarin analog. The fragment Gln(224)-Lys(232) has been identified as the modified peptide within the EF-2 sequence, Lys(228) being the residue to which the photoprobe was linked. This fragment is included within the G"-subdomain of EF-2. These results are discussed in the light of the high sordarin specificity toward fungal systems.

Mutation of POLG is associated with progressive external ophthalmoplegia characterized by mtDNA deletions

Progressive external ophthalmoplegias (PEO) characterized by accumulation of large-scale mitochondrial DNA (mtDNA) deletions are rare human diseases. We mapped a new locus for dominant PEO at 15q22-q26 in a Belgian pedigree and identified a heterozygous mutation (Y955C) in the polymerase motif B of the mtDNA polymerase gamma (POLG). We identified three additional POLG missense mutations compatible with recessive PEO In two nuclear families. POLG is the only DNA polymerase responsible for mtDNA replication.

Light adaptation: night vision goggle effect on cockpit instrument reading time

BACKGROUND

Light adaptation to the intensified image provided by a night vision device may handicap pilots who have set cockpit instrument luminance too low.

METHODS

Under conditions simulating night flying, subjects adapted to an NVG image at 3 or 10 footlamberts (fL), then used a joystick to indicate the position of the horizon in an ADI illuminated by NVIS-compatible light at luminances 2 to 3.5 log units lower than the NVG image.

RESULTS

Response times increased no more than a few tenths of a second when the decrease in luminance was only 2 log units. Greater decreases produced correspondingly longer delays in response, reaching as much as 5.5 s for subjects in their twenties and 8-15 s for older subjects.

CONCLUSIONS

While a decrease of more than 2 log units is not likely to occur under most operational conditions, it is certainly possible, and pilots should be aware that significant risk can be incurred by setting cockpit instruments to luminance levels below 0.03 fL.

The many faces of human prion diseases in Belgium and the world

Prion diseases are rare neurodegenerative disorders that always lead to death and that can be transmissible under certain conditions. Although sporadic Creutzfeldt-Jakob's disease (CJD) is the best known human variant of these transmissible spongiform encephalopathies with an incidence of about 1 in 106 inhabitants, several other types of human prion disease have been described (e.g. Familial CJD, Gerstmann-Sträussler-Scheinker syndrome, Fatal Familial Insomnia,...). In 1996, a variant of CJD has been linked to the epidemic of bovine spongiform encephalopathy (BSE). Therefore, vigilance concerning prion diseases was increased throughout the whole of Europe. In Belgium, a comprehensive, nation-wide study has been conducted both retrospectively (1960-1997) and prospectively (1998-...) to identify prion disease patients. In 1998, a surveillance system has also been created to monitor the incidence of CJD and other prion diseases. Using data from both studies and the surveillance program, the occurrence and phenotype of all types of prion diseases in Belgium was investigated. The sporadic type of CJD was identified in 116 patients, while 4 suffered from a hereditary form. In our series, we could find no evidence for variant or iatrogenic CJD, neither for the more rare types of prion diseases.

A novel 3′-splice site mutation in peripheral myelin protein 22 causing hereditary neuropathy with liability to pressure palsies

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant, demyelinating peripheral neuropathy. Clinical hallmarks are recurrent painless focal neuropathies mostly preceded by minor trauma or compression at entrapment sites of peripheral nerves. In the majority of the patients, HNPP is caused by a 1.5 Mb deletion on chromosome 17p11.2-p12 containing the peripheral myelin protein 22 (PMP22) gene. Point mutations within this gene are reported in only a few families. We report a novel mutation in the PMP22 gene in a Spanish family with HNPP. The mutation is a 3' splice-site mutation, preceding coding exon 3 (c.179-1 G>C), causing a mild HNPP phenotype.

Detection of cytokines in human sural nerve biopsies: an immunohistochemical and molecular study

In vitro and in vivo models have implicated numerous cytokines as major modulators of inflammation, destruction and repair in the peripheral nervous system (PNS). The in situ production of cytokines in human peripheral nerve disorders is still poorly documented. We studied the expression of interleukin (IL)-1 beta, tumor necrosis factor (TNF)-alpha, IL-6, IL-10, IL-4, IL-3 and nerve growth factor (NGF) in 35 human sural nerve biopsies using immunohistochemistry; additional reverse transcription-polymerase chain reaction and mRNA in situ hybridization were performed for IL-4 and NGF. Expression of IL-1 beta and TNF-alpha was shown in both morphologically normal nerves and various neuropathies, and macrophages appeared as their predominant source. Levels of IL-1 beta and TNF-alpha expression were significantly correlated (P < 0.01) with each other and with expression of NGF. Multiple endoneurial sources were suggested for IL-6 and IL-10 with low immunoreactivity in the vast majority of cases. Conversely, IL-4 and IL-3 expression were found in neuropathies of various etiologies and Schwann cells appeared to be a predominant source of IL-4 in double-labeling immunofluorescence studies. IL-3 immunoreactivity correlated with IL-1 beta, TNF-alpha and IL-6. In this retrospective study, no specific cytokine profile of expression could be assigned to a precise subgroup of neuropathies. This is the first report of IL-4 and IL-3 expression in human neuropathies, and it may be important given the potential role of these cytokines in modulating macrophage activity in the PNS.

Further evidence that neurofilament light chain gene mutations can cause Charcot-Marie-Tooth disease type 2E

A missense mutation in the neurofilament light chain gene (NEFL, NF-L) at chromosome 8p21 was recently reported in a single Charcot-Marie-Tooth type 2 family (CMT2). This new CMT2 variant is designated CMT2E. The NEFL gene mutation showed co-segregation with the disease phenotype and is thus most likely the disease-causing mutation. However, the possibility that it is a closely linked rare polymorphism can not be ruled out with certainty. We observed a novel NEFL missense mutation in a second CMT family, providing supporting evidence that CMT2E is caused by NEFL gene mutations.

Phonological agraphia following a focal anterior insulo-opercular infarction

Following a unique infarction, restricted to the left anterior insula and the adjacent part of the intrasylvian frontal opercular cortex, an 83-year-old right-handed patient acutely developed a severe speech disorder that evolved into mere mutism within a few hours. After rapid recovery from mutism, oral language was characterized by severe apraxia of speech. In-depth language investigations further disclosed an isolated, highly selective disturbance of the spelling system (phonological agraphia) which resolved rapidly. One year after onset of neurological symptoms, the apraxia of speech had almost completely receded. The anatomoclinical findings in this first representative of pure and nearly isolated phonological agraphia complement previous neuroanatomical and neurolinguistic accounts of phonological agraphia. The data not only seem to enrich current insights in the anatomical locus for phonological agraphia, they also seem to contribute to a further delineation of the insular role in phonologically mediated aphasic manifestations.

Variant Alzheimer's disease with spastic paraparesis and cotton wool plaques is caused by PS-1 mutations that lead to exceptionally high amyloid-beta concentrations

We describe 3 new families affected by Alzheimer's disease with spastic paraparesis. In affected individuals, including the earliest known patient with this clinical syndrome, neuropathological examination revealed large "cotton wool" plaques similar to those we have previously described in a Finnish family. In the families in which DNA was available, presenilin-1 mutations were observed. Transfection of cells with these mutant genes caused exceptionally large increases in secreted Abeta42 levels. Furthermore, brain tissue from individuals with this syndrome had very high amyloid-beta concentrations. These findings define the molecular pathogenesis of an important subgroup of Alzheimer's disease and have implications for the pathogenesis of the disease in general.

Charcot-Marie-Tooth disease and related peripheral neuropathies

Soon after the description of Charcot-Marie-Tooth disease (CMT) in 1886, it became apparent that this syndrome is clinically and genetically heterogeneous. Neuropathological and electrophysiological studies have further dissected this syndrome into distinct categories that are now classified in a complex nosology of the inherited peripheral neuropathies. The recent advent of molecular genetics has dramatically increased our understanding of the underlying disease mechanisms. Genetic linkage studies have identified at least 17 genetic loci for different types of inherited neuropathies although most genes involved still remain to be found. The application of molecular genetics has already had an important impact on clinical practice and genetic counselling. Three genes responsible for hereditary motor and sensory neuropathy type I (HMSNI) or CMT1 have been identified: peripheral myelin protein 22 (PMP22) and myelin protein zero (MPZ) for the autosomal dominant form and connexin 32 (Cx32) for the X-linked dominant variant. The PMP22 gene is also involved in the majority of families with hereditary neuropathy with liability to pressure palsies (HNPP). The observation of a 1.5 Mb tandem duplication in chromosome 17p11.2, containing the PMP22 gene, in CMT1 and the reciprocal deletion in the same region in HNPP has provided a novel disease paradigm for autosomal dominant disorders, i.e. the gene dosage mechanism. The study of phenotype-genotype correlations in transgenic animal models for PMP22, MPZ and Cx32 mutations will help elucidate the underlying disease mechanisms and will provide a basis for gene therapy and/or other therapeutic approaches such as treatment with neurotrophic growth factors.