Unicentric Portocaval Castleman Disease in an Adolescent: Challenges in Diagnosis and Management.

Castleman disease is an unusual, benign disorder of unknown etiology, characterized by the proliferation of the lymphoid tissue. It can have a unicentric or multicentric presentation, depending on the number of lymph nodes involved. On clinical examination and imaging, it can imitate a malignancy and the diagnosis can only be confirmed on histopathological examination. Retroperitoneal location and presentation in the pediatric age group are extremely rare. We report a case of an adolescent girl with a unicentric lymph nodal mass in the portocaval space which was completely excised.

Temporal lobe angiocentric glioma with oligodendroglioma-like areas: a rare association of an uncommon tumor. A case report with review of literature.

BACKGROUND: Angiocentric glioma (AG) is a relatively uncommon clinico-pathological entity that presents in childhood. Angiocentric glioma displays various histopathological features which resemble cortical ependymoma, astroblastoma, and pilomyxoid astrocytoma and schwannoma. The astrocytes in angiocentric glioma appear peculiarly elongated, bipolar in shape, and characteristically arranged around blood vessels. They resemble radial glia and tanycytes morphologically. Unlike ependymomas, AG is a diffusely infiltrating lesion and perivascular processes are often much thicker than those in classic ependymomas. CASE PRESENTATION: AG usually present clinically as seizures, often as medically intractable epilepsy. In the indexed case, apart from unusual presentation with features of raised intra-cranial tension, an unusual histological picture of a more cellular oligodendroglioma like component was also seen. CONCLUSION: The appropriate diagnosis is critical as AG is usually slowly growing and treatable by surgical excision alone.

Recurrent or symptomatic residual posterior fossa hemangioblastomas: how are they different from their primary counterparts?

BACKGROUND: Posterior fossa hemangioblastomas are WHO grade I benign lesions with a surprisingly high recurrence rate. This study determines the factors responsible for recurrence and the clinico-radiological and histopathological differences between primary (group A; n = 60) and recurrent/symptomatic residual (group B; n = 24) tumors. METHODS: Radiologically, tumors were differentiated into cystic, cystic with a mural nodule, solid-cystic/microcystic and solid. Surgery was undertaken via a midline or lateral suboccipital approach. Histopathology differentiated them into reticular, cellular or mixed subtypes. RESULTS: Truncal-appendicular ataxia in group A and von Hippel-Lindau (VHL) disease and raised intracranial pressure in group B were the predominant presentations. VHL patients in group B had a longer duration of symptoms (median 72 months) than those with non-VHL recurrences (median: 36 months). Multicentric mural nodules (n = 9/24, 37.50%, P = 0.0001) and bilateral cerebellar hemispheric involvement (n = 6/24, 25%, P = 0.0003) were exclusively seen in the preoperative radiology of group B tumors. Brainstem involvement was seen in the tumors of ten (16.67%) patients in group A and six (25.00%) patients in group B. One subset of patients required several resurgeries for repeated recurrences. Abnormal vascular proliferation and papillary projections into adjacent brain, and highly cellular stroma were unique histological features at recurrence. Total resection was achieved in 45 group A and 19 group B patients. The outcome based on the Karnofsky performance scale (KPS) was assessed at follow-up at 6 weeks (A: n = 60, B: n = 24): KPS0: A = 4, B = 1; KPS10-40 (dependent): A: 4, B = 5; KPS50-70 (independent for daily needs): A = 36, B = 16; KPS80-100 (fully independent): A = 16; B = 2. CONCLUSIONS: In recurrent/residual tumors, the radiological as well as histopathological features showed a distinctive change toward a more aggressive nature. Higher incidences of multiple mural nodules, bilateral spread, remote recurrence and VHL disease at preoperative radiology; as well as proliferative angioarchitecture, an irregular brain tumor interface and highly cellular stroma at histology were found in these patients compared to their primary counterparts.

3D Virtual Bronchoscopy as an Aid to Airway Management in a Patient with Anterior Mediastinal Mass.

ABSTRACT: Mediastinal masses pose one of the great challenges for any anesthesiologist during airway maintenance, underlining the need to devise a well-formulated plan to avoid perioperative complications. As a general rule, such patients are managed with spontaneous ventilation without the use of muscle relaxants and awake intubation. We report a case of a 66-year-old male with severe dyspnea, having a very large invasive anterior mediastinal mass, causing left lung collapse for urgent debulking surgery. The tracheobronchial compromise was ruled out using three-dimensional reconstruction on computed tomography imaging (virtual bronchoscopy) and that helped in using general anesthesia with muscle relaxation for subsequent endotracheal intubation and surgery.

Seizure-outcome after surgery of low-grade epilepsy associated neuro-epithelial tumors.

BACKGROUND: Most patients with glioneuronal tumors present with seizures. Although several studies have shown that greater extent of resection improves overall patient survival, few studies have focused on postoperative seizure outcome after resection of these tumors. The aim of this study was to characterize seizure control rates in patients undergoing glioneuronal tumor resection and evaluate the association between poor seizure outcome and tumor recurrence or progression. METHODS: The study population included patients who had undergone resection of glioneuronal tumors between 2014 and 2019 at our institution. Seizure outcome was assessed using Engel grading. Preoperative seizure characteristics, tumor characteristics, surgical factors, and postoperative seizure outcomes were reviewed. RESULTS: Twenty-six patients (N.=16, temporal lobe; N.=6, frontal lobe; N.=4, parietal lobe) with mean seizures duration of 56.9-months, were assessed. Histopathologically, N.=15 dysembryoplastic neurepithelial tumor, N.=7 ganglioglioma and N.=4 Diffuse lepto-meningeal neuroepithelial tumor. There were 2 cases of complex DNET and one case of DLMNT had associated cortical dysplasia. At mean follow-up of 49.7 months, N.=20 Engel 1, N.=4 Engel 2 and N.=2 had Engel 3 outcome. N.=20 underwent gross total excision (N.=18 Engel 1 and N.=2 Engel 2) and N.=6 sub-total excision. Among the 4 patients who needed re-surgery, two were in Engel 2 and another two were in Engel 3. CONCLUSIONS: Good seizure-outcome is likely associated with extent of resection. Younger age of patient, less than one-year of seizure duration and absence of generalization of seizure are good prognostic indicators. The best seizure-control can be achieved by early surgical intervention.

Lipomatous meningioma: a study of five cases with brief review of literature.

Lipomatous meningiomas are an uncommon subtype of meningiomas. In the present report, the clinical characteristics, neuroimaing and pathological features of 5 patients (4 males, 1 female; age range, 17-45 years; mean age, 35.2 years) with lipomatous meningioma were analyzed. The neuro-pathological reevaluation of lipomatous meningioma involved assessment of histological features proposed by the current WHO classification. The presence or absence of high whorls, fascicles, solid growth, glial invasion, necrosis and nuclear pleomorphism was assessed. The most common presenting symptom was seizures. Location of tumor was frontal (3 cases), parietal (1 case) and fronto-temporal (1 case). All cases showed radiological features of conventional meningioma. Complete excision of tumor along with involved dura was performed in all the patients. Three tumors were meningothelial and 2 were transitional. Tumoral lipid content was variable from 10% to 30%. In addition, there were microcystic features (2 cases) and psammoma bodies (1 case). No recurrence was noted in any of our cases till the last follow-up. Lipomatous meningioma represents a rare distinctive type of meningioma, with a good prognosis with complete removal.

Human sodium iodide symporter (hNIS) in fibroadenoma breast--a immunohistochemical study.

Human sodium iodide symporter (hNIS), responsible for the active transport of iodine is an integral plasma membrane glycoprotein present in the thyroid cells and extrathyroid tissues like breast and salivary glands. If its functional form is unequivocally shown in benign or malignant breast tissues, then it may serve as a basis for diagnosis and treatment using radioactive iodine. With an aim to analyze the hNIS expression in a distinct benign breast condition of fibroadenoma, biopsy proven fibroadenoma tissues, normal non-lactating breast tissue and biopsy proven infiltrating duct carcinoma tissues were examined for hNIS expression using immunohistochemistry. Out of 20 biopsy proven fibroadenoma tissues, 19 (95%) showed positivity for hNIS protein and only one was negative. Of these 10% were mildly positive, 50% cases were moderately positive and 35% showed intense positivity. None of the control tissue obtained from reduction mammoplasty specimens or normal breast tissues samples (5 cms away from the tumor) were positive, hNIS was also intensely positive in 9 out of 10 (90%) infiltrating duct carcinoma tissues and moderately positive in one case. These preliminary results show that hNIS was present in high frequency as demonstrated by immunohistochemistry in fibroadenoma breast.

Seizure Outcome after Lesionectomy With or Without Concomitant Anteromedial Temporal Lobectomy for Low-Grade Gliomas of the Medial Temporal Lobe.

BACKGROUND: Mesial temporal lobe epilepsy attributed to low-grade glioma is known for intractable seizures and choice of surgery range from lesionectomy (Lo) to lesionectomy with anteromesial temporal resection (L0 + AMTR) is still debatable. We intend to analyze the seizure outcome after lesionectomy alone or with AMTR. SUBJECTS AND METHODS: Retrospective analyses of patients operated for medial low-grade temporal lobe tumors with seizures were included in the study. Preoperative records include video-electroencephalographic, magnetic resonance imaging (epilepsy protocol), and neuropsychological evaluation for language, memory, and dominance were assessed. Two groups (Lo [Group I] and Lo + AMTR [Group II]) were assessed after surgery by the international league against epilepsy (ILAE) seizure outcome scale. RESULTS: A total of 39 patients underwent Lo (n = 20) and Lo + AMTR (n = 19) with a mean age of 26.92 ± 12.96 months, and mean duration of seizures was 36.87 46.76 months. A total of 23 patients had long-term intractable seizures for >1 year despite >2 drugs(Group I [n = 10], Group II [n = 13]); remaining 16 had frequent seizures of <1-year duration. In the postoperative period, on a mean follow-up of 49.72 ± 34.10 months, the ILAE outcome scale shown a significant difference (P = 0.05) in seizure outcome between two groups. Four (40%) patients out of 10 having refractory seizures in Group I and 8 (80%) from the Group II out of 10 patients could achieved ILAE Class 1 outcome after surgery. Histopathology analysis includes low-grade astrocytoma (n = 29) and in two patients there were associated CA1 neuronal loss in hippocampus, one patient had mesial temporal sclerosis from Group II attributed to its intractability in seizures. CONCLUSION: For the mesial temporal low-grade glioma presenting with seizures, the seizure outcome by lesionectomy with AMTR is superior than lesionectomy only.

An unusual case of Microascus brain abscess in an immunocompetent child and a review of the literature.

We present a case of brain abscess in an immunocompetent child due to the dematiaceous fungus Microascus cinereus, an organism commonly found in soil and stored grains. The etiologic agent was demonstrated by direct microscopy and culture. The patient responded well to surgical excision of abscess along with a course of amphotericin B and voriconazole. Microascus species have emerged as significant invasive pathogens especially in the immunocompromised patients. To the best of our knowledge, this is the first reported case of brain abscess caused by M. cinereus in an immunocompetent individual with no underlying risk factors.

Long-Term Epilepsy-Associated Tumors (LEATs): A Single-Center, Retrospective Series and Review of Literature on Factors Affecting the Seizure Outcome.

BACKGROUND: Tumors presenting with drug-resistant seizures are termed as long-term epilepsy-associated tumors (LEATs). LEATs are more common in the temporal lobe, occur predominantly in pediatric age, and focal neurological deficits are rare. In this article, we aim to highlight our surgical experience in terms of seizure outcome among LEATs and discuss the factors affecting outcome. METHODOLOGY: We have retrospectively analyzed all the operated cases of intra-axial brain tumors with seizures (2015-2019). The clinical and radiographic data were collected from the hospital record system. For comparison, 2 groups were made (group 1 with good seizure control, i.e., Engel 1; and group 2 poor seizure outcome, i.e., Engel 2 and 3). RESULTS: A total of 51 cases were included; the temporal lobe was the most common location (n = 27); 23 patients had seizure frequency of "more than 1 seizure per week." Focal unaware seizures/complex partial seizures were the most common type of seizures encountered (n = 28). At a mean follow-up of 39.60 months, 38 patients had Engel 1 (78.5%) outcome (35 cases [71.05%] had the seizure duration of ≤2 years). The median duration of symptoms (group 1, 25 months vs. group 2, 65 months) was significantly different (P = 0.002). On comparing patients with seizure duration, we found a statistically significant difference (P < 0.00001). CONCLUSION: A shorter duration of symptoms, younger age of the patient, partial/focal seizures, and gross total excision were predictors of a good seizure outcome. Histopathology of the tumor does not affect the outcome when one compares glioneuronal tumors with non-glioneuronal tumors.

Isolated Intraventricular Chronic Mucormycosis in an Immunocompetent Infant: A Rare Case with Review of the Literature.

BACKGROUND: Mucormycosis of the central nervous system is an uncommon infection caused by saprophytic or parasitic fungi of the subphylum Mucormycotina and order Mucorales viz. Rhizopus, Mucor, and Rhizomucor. Isolated, chronic involvement of the central nervous system is a rare occurrence. To the best of our knowledge, isolated chronic ventricular involvement in an infant has not been reported previously. Isolated intracerebral mucormycosis is a disease of the immunocompromised patient, and to date only 6 cases have been reported in immunocompetent patients, including 2 pediatric cases. CASE DESCRIPTION: We present the case of an immunocompetent infant presenting with features of increased intracranial tension. He underwent cerebrospinal fluid diversion and was found to harbor mucormycosis on histopathologic examination of intraventricular debris. We also present a brief review of the relevant literature. CONCLUSIONS: Although mucormycosis is an acute fulminant infection, chronic isolated cerebral cases are known in the immunocompetent patient. Patients also may present with isolated hydrocephalus, and hence fungal infection must be ruled out in all, especially if a shunt is warranted.

Elevated FGF23 in a patient with hypophosphatemic osteomalacia associated with neurofibromatosis type 1.

CONTEXT: The mechanism behind hypophosphatemia in the setting of neurofibromatosis type 1 (NF1) is not known. We describe a possible role of fibroblast growth factor-23 (FGF23) in the pathophysiology of hypophosphatemia in a patient with NF1. CASE DESCRIPTION: A 34-year woman with NF1 presented with severe hypophosphatemia, osteomalacia, and elevated plasma FGF23. The patient had considerable improvement on replacement of oral phosphate. Two Ga68 DOTANOC PET-CT scans over a period of 2 years failed to detect any localized uptake. Immuno-staining for FGF23 was absent in the neural-derived tumour cells of the neurofibromas in the proband. CONCLUSION: The patient with NF1 had elevated circulating FGF23. Tumour cells in the neurofibroma tissues did not stain for FGF23 on IHC. It is unlikely for neurofibromas to contribute to high circulating FGF23 levels in the proband.

A clinical, electrophysiological, and pathological study of neuropathy in rheumatoid arthritis.

Neuropathy in rheumatoid arthritis (RA) may result secondary to entrapment, vasculitis, and drug toxicity. We aimed to study clinical and electrophysiological neuropathy and pathological changes in sural nerve in patients with RA. One hundred eight patients of RA, fulfilling American College of Rheumatology 1987 criteria (mean age, 45.83 years; M/F 1:3, 80.3% seropositive) were examined clinically and electrophysiologically for evidence of peripheral neuropathy. Sural nerve biopsies were performed in the involved cases. In all RA patient medications, disease activity, results of blood tests, and X-rays of affected joints were recorded. Twenty-three patients complained of paresthesias in the extremities. Vibration sensations were decreased in 9, and tendon reflexes were decreased or absent in 28 patients. Sixty-two (57.4%) patients had electrophysiologic evidence of neuropathy. Of these 53 (85.5%) patients had pure sensory or sensory motor axonal neuropathy (mononeuritis multiplex, n = 7), while 9 (14.5%) had demyelinating neuropathy (chronic inflammatory demyelinating polyneuropathy, n = 1). Carpal tunnel syndrome was seen in 11 (10.1%) patients (associated with neuropathy in 6). Of 23 sural nerve biopsies available, perineurial thickening (n = 5, amyloid deposits n = 4), perivascular lymphomononuclear cell infiltrate (n = 4), loss of myelin fibers (n = 2), and necrotizing vasculitis (n = 1) were found. Clinically, however, seven patients had evidence of cutaneous vasculitis. Comparing the clinical characteristics of the patients with or without electrophysiological neuropathy, absence of deep tendon jerks (p < 0.005) and presence of extra articular manifestations (p < 0.01) were conspicuous in the neuropathic group. There was no relation of neuropathy with the duration of RA, seropositivity, joint erosions, joint deformities, prior disease-modifying anti-rheumatic drugs or glucocorticoid intake, and 28-joint disease activity score. Neuropathy in RA was mostly subclinical and predominantly axonal. Pathologically, neuropathy secondary to amyloid infiltration was second only to vasculitic neuropathy. Absence of deep tendon jerks and presence of vasculitis were more commonly observed in patients with neuropathy.

Gliomatosis cerebri--an uncommon neuroepithelial tumor in children with oligodendroglial phenotype.

Gliomatosis cerebri(GC) is a highly aggressive, rare form of neuroepithelial tumor. Due to the diffuse nature of the tumor, its pathological grade is not conclusively established unless a biopsy is carried out from multiple sites. The tumor typically infiltrates the cortex in the subpial plane and also insinuates in the perineuronal space and around the Virchow-Robin spaces with relative preservation of the underlying brain parenchyma. Most of the previously reported cases of GC are astrocytic in nature. In this study, we report 2 pediatric patients of GC with oligodendroglial morphology on histopathological examination. In view of the rarity of the oligodendroglial phenotype of gliomatosis cerebri as well as the rare occurrence in children, we report these 2 cases.

Cerebellar Liponeurocytoma: The Dilemma of Multifocality.

BACKGROUND: Cerebellar liponeurocytoma (cLNC) is a rare benign glioneuronal tumor with only ~60 cases reported since its first description in 1978. They have occurred largely as sporadic cases; however, familial cases with possible autosomal dominant inheritance have also been reported. Surgical excision has been considered the main modality of treatment, even for recurrent lesions. Uncertainties exist regarding the natural history, long-term outcomes, and optimal postoperative management and follow-up protocols for cLNC in general and multifocal cLNC in particular. Multifocality is exceedingly rare, with only 4 cases reported previously. CASE DESCRIPTION: We present a case of multifocal cLNC in a young woman who had presented with progressive cerebellar symptoms of 5 months' duration. Her diagnostic neuroimaging evaluations revealed 2 asymmetric mass lesions (1 on each cerebellar hemisphere). We excised the larger lesion to relieve the mass effect and decided to monitor the smaller lesion radiologically. However, she developed a new lesion during the follow-up period and required adjuvant radiotherapy. CONCLUSION: Surgical excision forms the cornerstone of management of cLNCs. However, it is necessary to vigilantly monitor these patients owing to the high recurrence rates of cLNC despite the innocuous histologic features.

Intracranial Peripheral Primitive Neuroectodermal Tumor Arising from the Clivus with Intracranial Metastasis in an Elderly Woman: Case Report and Review of the Literature.

BACKGROUND: Intracranial peripheral primitive neuroectodermal tumors (pPNETs) are rare lesions, accounting for only 1% of all pPNETs, and usually arise from bone and soft tissue. These tumors primarily affect young patients (<30 years old) and rarely affect older patients. The common intracranial locations of these lesions are frontal dura and tentorium. These lesions rarely may involve the cerebellopontine angle, cavernous sinus, and jugular foramen. Involvement of clivus has not been reported to date. Intracranial metastasis from primary intracranial pPNET is a further rare occurrence. CASE DESCRIPTION: A 74-year-old woman presented with gradually progressive painless diminution of vision in both eyes alongwith headache for 6 months duration. Radiology demonstrated a clival mass as well as a suspected intracranial metastasis. Histopathology was suggestive of pPNET. We also present a brief review of the literature on pPNETs. CONCLUSIONS: pPNETs of the clival region are exceptionally rare. In elderly patients with clival mass lesions, the rare possibility of pPNET should be kept in mind.

An Infratentorial Pure Pleomorphic Xanthoastrocytoma Arising from Middle Cerebellar Peduncle: A Rare Location of an Uncommon Tumor.

BACKGROUND: Pleomorphic xanthoastrocytomas are rare tumors of glial origin comprising <1% of all astrocytic tumors of brain. These tumors are rare in the infratentorial compartment and were not known to arise from the middle cerebellar peduncle. CASE DESCRIPTION: We discuss the case of a 16-year-boy who presented with altered sensorium and features of increased intracranial pressure and was found to have a 4 × 4 × 3 cm mass arising from the middle cerebellar peduncle. CONCLUSION: We also discuss the histopathologic features of these tumors suggesting their resemblance to other maldevelopmental tumors, the rarity of pure World Health Organization grade II pleomorphic xanthoastrocytoma in the infratentorial compartment, as well as the appropriate management.

Extraosseous Primary Intracranial Ewing Sarcoma/peripheral Primitive Neuroectodermal Tumor: Series of Seven Cases and Review of Literature.

BACKGROUND: The Ewing sarcoma peripheral PNET (ES-pPNET) is very rare small round cell tumour that involves the CNS as either a primary dural neoplasm or by direct extension from contiguous bone or soft tissue. MATERIALS AND METHODS: Biopsy proven cases of intracranial ES/pPNET with orbital involvement operated during Jan 2010-Jan 2014 were retrospectively included and their clinical data, operative and histological findings were reviewed from institutional oncology register. RESULTS: seven patients (4 males; 3 female) were studied with mean age at presentation of 13 years. Six patients had orbital involvement in one or other form. Surgical excision was gross total in five, near total in one, and subtotal in one patient. All patients received adjuvant therapy, only chemotherapy in 2, only Radiotherapy in four, both in one. MRI characteristics were studied in six patients. Four patients died with average survival of 33.2 months and three patients are having Progression free survival of average 23.3 months. CONCLUSIONS: The EWS-pPNET is very rare tumour and very poorly described in literature. These tumours are showing special predilection for the frontotemporal dura and erode through the flat bone of cranium like orbital roof and lateral wall of the orbit. These tumours are aggressive, multi compartmental, vascular and very rapidly growing, so missing or overlooking the primary symptoms of dural stretching/bony involvement leads to delay in management and poor outcome.

Abnormal lipid metabolism in skeletal muscle tissue of patients with muscular dystrophy: In vitro, high-resolution NMR spectroscopy based observation in early phase of the disease.

PURPOSE: Qualitative (assignment of lipid components) and quantitative (quantification of lipid components) analysis of lipid components were performed in skeletal muscle tissue of patients with muscular dystrophy in early phase of the disease as compared to control/normal subjects. METHODS: Proton nuclear magnetic resonance (NMR) spectroscopy based experiment was performed on the lipid extract of skeletal muscle tissue of patients with muscular dystrophy in early phase of the disease and normal individuals for the analysis of lipid components [triglycerides, phospholipids, total cholesterol and unsaturated fatty acids (arachidonic, linolenic and linoleic acid)]. Specimens of muscle tissue were obtained from patients with Duchenne muscular dystrophy (DMD) [n=11; Age, Mean±SD; 9.2±1.4years; all were males], Becker muscular dystrophy (BMD) [n=12; Age, Mean±SD; 21.4±5.0years; all were males], facioscapulohumeral muscular dystrophy (FSHD) [n=11; Age, Mean±SD; 23.7±7.5years; all were males] and limb girdle muscular dystrophy-2B (LGMD-2B) [n=18; Age, Mean±SD; 24.2±4.1years; all were males]. Muscle specimens were also obtained from [n=30; Mean age±SD 23.1±6.0years; all were males] normal/control subjects. RESULTS: Assigned lipid components in skeletal muscle tissue were triglycerides (TG), phospholipids (PL), total cholesterol (CHOL) and unsaturated fatty acids (arachidonic, linolenic and linoleic acid)]. Quantity of lipid components was observed in skeletal muscle tissue of DMD, BMD, FSHD and LGMD-2B patients as compared to control/normal subjects. TG was significantly elevated in muscle tissue of DMD, BMD and LGMD-2B patients. Increase level of CHOL was found only in muscle of DMD patients. Level of PL was found insignificant for DMD, BMD and LGMD-2B patients. Quantity of TG, PL and CHOL was unaltered in the muscle of patients with FSHD as compared to control/normal subjects. Linoleic acids were significantly reduced in muscle tissue of DMD, BMD, FSHD and LGMD-2B as compared to normal/control individuals. CONCLUSIONS: Results clearly indicate alteration of lipid metabolism in patients with muscular dystrophy in early phase of the disease. Moreover, further evaluation is required to understand whether these changes are primary or secondary to muscular dystrophy. In future, these findings may prove an additional and improved approach for the diagnosis of different forms of muscular dystrophy.

Increased pro-nerve growth factor and p75 neurotrophin receptor levels in developing hypothyroid rat cerebral cortex are associated with enhanced apoptosis.

Thyroid hormone insufficiency adversely affects cortical development; however, its effect on apoptosis modulation during cerebral cortex development is not understood. We investigated the effect of perinatal hypothyroidism on apoptosis and its mechanisms during rat cerebral cortex development. Primary hypothyroidism was induced by feeding methimazole (0.025% wt/vol) in the drinking water to pregnant and lactating rats and continued until the animals were killed (hypothyroid group). Cerebral cortices from pups were harvested at different postnatal ages (postnatal d 0, 8, 16, and 24 and adult), and apoptosis was quantitated by terminal deoxynucleotide transferase-mediated dUTP nick end labeling and cleaved caspase-3 immunoreactivity. Compared with the euthyroid, primary somatosensory cortex (S1) in the hypothyroid group exhibited enhanced apoptosis. In S1 of euthyroid rats, apoptotic cells were mostly found in cortical layers I-III and the proportion of apoptotic cells enhanced significantly in the hypothyroid group (P < 0.001). Most of the apoptotic cells were neurons, as assessed by double immunolabeling. A significantly increased activation of caspase-3 and -7, decreased levels of antiapoptotic proteins Bcl-2 and Bcl-x(L), and increased levels of proapoptotic protein Bax was observed in the developing cerebral cortex of hypothyroid rats, compared with the euthyroid (P < 0.001). In addition, hypothyroidism significantly elevated the levels of 53-kDa pro-nerve growth factor (P < 0.001) and p75 neurotrophin receptor (P < 0.001) and decreased TrkA expression. Taken together, we provide evidence for the possible contribution of pro-nerve growth factor/p75 neurotrophin receptor pathway in hypothyroidism-enhanced apoptosis during rat cortical development. Thus, the present study may help in explaining the mechanism of the deleterious effect of thyroid hormone deficiency on cerebral cortex development in children.