A Latent Propriospinal Network Can Restore Diaphragm Function after High Cervical Spinal Cord Injury

Spinal cord injury (SCI) above cervical level 4 disrupts descending axons from the medulla that innervate phrenic motor neurons, causing permanent paralysis of the diaphragm. Using an ex vivo preparation in neonatal mice, we have identified an excitatory spinal network that can direct phrenic motor bursting in the absence of medullary input. After complete cervical SCI, blockade of fast inhibitory synaptic transmission caused spontaneous, bilaterally coordinated phrenic bursting. Here, spinal cord glutamatergic neurons were both sufficient and necessary for the induction of phrenic bursts. Direct stimulation of phrenic motor neurons was insufficient to evoke burst activity. Transection and pharmacological manipulations showed that this spinal network acts independently of medullary circuits that normally generate inspiration, suggesting a distinct non-respiratory function. We further show that this "latent" network can be harnessed to restore diaphragm function after high cervical SCI in adult mice and rats.

Multiple pleural nodules without effusion--a rare presentation of tuberculous pleurisy

We report a rare case of tuberculous pleurisy presenting with multiple pleural nodules without associated effusion or parenchymal lung lesions. A 62-year-old man had multiple discrete pleural nodules in the right hemithorax on chest radiography without any clinical symptoms. Thoracoscopic biopsy of the pleural nodules revealed a caseous granuloma with acid-fast bacilli. The patient received antituberculous therapy, with resolution of tuberculomas on chest film within 2 months. To our knowledge, only two similar cases have been previously reported in the English literature, and our observation should lead to broadening of the spectrum of the differential diagnosis of multiple pleural nodules.

Chronic myeloid leukemia initially presenting with spontaneous mediastinal hematoma and hemothorax

Spontaneous mediastinal hematoma is rarely seen in hematologic malignancy. We report a case of chronic myeloid leukemia initially presenting with spontaneous hematoma and hemothorax. In addition to a detailed history, computerized tomography of the chest is important in analyzing whether an anterior mediastinal mass lesion is present. Magnetic resonance imaging is helpful in confirming the nature of a mediastinal hematoma. Trauma, vascular disease and coagulopathy should first be ruled out when making a diagnosis of spontaneous bleeding in the thorax. In our patient, the mediastinal hematoma regressed spontaneously after three months. Leukemia should be considered in the differential diagnosis of spontaneous mediastinal hematoma. In leukemia patients with spontaneous mediastinal hematoma, supportive observation and close follow-up may be better than surgery, unless massive hemorrhage or active bleeding in the thorax is suspected.

Ethambutol-induced psychosis: a case report

Clinically, ethambutol (EMB)-induced psychosis is rare. In our review of the literature, most cases of antituberculosis agent-associated psychoses were caused by isoniazid (INH). We report the case of a 51-year-old man with suspected tuberculosis (TB) pleurisy. An anti-TB trial with INH, rifampicin and EMB was given initially. Dizziness, disorientation, and auditory and visual hallucinations developed after seven days of therapy. Laboratory examinations, including routine biochemistry tests, serum titer of antinuclear antibodies, cerebrospinal fluid analysis and computerized tomography of the head showed no abnormal findings. Following discontinuation of anti-TB agents, the psychiatric symptoms subsided. When the patient was challenged with EMB, the same psychiatric symptoms recurred, but resolved again after discontinuation of EMB. It is important to be aware that EMB can induce psychosis when anti-TB medications are prescribed.

Intrathoracic extramedullary haematopoiesis complicated by massive haemothorax in alpha-thalassaemia

Intrathoracic extramedullary haematopoiesis (EMH) is a rare entity that is usually asymptomatic. A 44 year old man with alpha-thalassaemia is described who developed dyspnoea and massive left sided haemothorax. The haemoglobin disorder was established by Hgb H staining and haemoglobin electrophoretic studies. The DNA analysis revealed it to be a case of double heterozygous terminal codon mutation with the genotype alphaalphaCS/alphaalphaT. Computed tomographic scanning and magnetic resonance imaging of the thorax showed multiple paravertebral masses which were found by thoracoscopic biopsy to be extramedullary haematopoiesis. Although no additional sclerosing pleurodesis or low dose radiation therapy was given, the lung expanded well and there has been no recurrence of haemothorax to date.

Spindle cell carcinoma of the lung: a clinicopathologic presentation of three cases

Three patients with spindle cell carcinoma located in the lower respiratory tract are presented, including cases of two monophasic and one biphasic tumor. On light microscopic examination, the spindle cell components of the tumors were histologically characterized by sheets of fusiform spindle cells that closely resembled a sarcoma. Keratin expression in the spindle cell components of these tumors, as shown by anti-cytokeratin antibody staining, demonstrated their epithelial nature. It is supposed that the spindle cell component displays a spectrum of phenotypes originating from epithelial cells with varying degrees of mesenchymal transformation. It is difficult to establish a diagnosis of this rare primary pulmonary malignancy prior to surgical intervention. A review of the literature allowed for a summary of the clinicopathologic characteristics of this tumor.