Different underlying pain mechanisms despite identical pain characteristics: a case report of a patient with spinal cord injury.

Pain following spinal cord injury has been classified as nociceptive (musculoskeletal, visceral) or neuropathic (above, at, below level). There is no clear relation between the etiology and reported symptoms. Thus, due to different underlying mechanisms, the treatment is often ineffective. We report on a patient with spinal cord injury with neurological level of injury at T8 suffering from bilateral burning and prickling pain in the T9-11 dermatomes bilaterally (at-level pain), as well as diffusely in both legs from below the torso (below-level pain), accompanied by musculoskeletal low back pain. Bilateral comparison of quantitative sensory testing (QST) and skin biopsy revealed completely different findings in the dermatome T9 despite identical at-level pain characteristics. On the right side, QST revealed a normal sensory profile; the intraepidermal nerve fiber density (IENFD) was reduced, but not as severe as the contralateral side. On the left side there was a severe sensory loss with a stronger reduction of the IENDF, similar to the areas below the neurological level. These findings were significantly related to the treatment results. Pregabalin induced unilateral pain relief only in the area with remaining sensory function, whereas the left-sided at-level pain was unchanged. Thus, 2 different underlying mechanisms leading to bilaterally neuropathic pain with identical symptoms and with different treatment success were demonstrated in a single patient. The at-level pain in areas with remaining sensory function despite IENFD reduction could be relieved by pregabalin. Thus, in an individual case, QST may be helpful to better understand pain-generating mechanisms and to initiate successful treatment.

Intramedullary spinal cord metastasis and multiple brain metastases from urothelial carcinoma.

Intramedullary spinal cord metastases (ISCM) are rare spinal cord neoplasms associated with severe neurological deterioration and poor life expectancy. However, their incidence is expected to increase as a result of advances in diagnostic techniques and longer survival of patients with cancer due to improvements in cancer therapy. Reports on ISCM from primary urothelial carcinoma are virtually non existent. We report a 74-year-old male patient with a significant history of a high-grade urothelial carcinoma who presented with progressive back pain and concomitant weakness, grade 3-4/5 proximally and 0-1/5 distally, and distal hyperesthesia and hyperalgesia, particularly of the left lower limb. MRI revealed a contrast-enhancing intramedullary lesion at Th11/Th12. Laminectomies of Th11/Th12 and lesion resection were performed. Postoperative histopathological examinations confirmed the metastatic nature of the lesion. Subsequently the patient developed multiple brain metastases. Radiation therapy was refused by the patient. We conclude that ISCM are devastating complications of systemic cancer. Early and thorough diagnosis, as well as carefully considered and prompt therapy, is important for minimizing the patient's functional deficit, thus improving quality of life.

Primary carcinoid tumor of the filum terminale--a case report.

Carcinoid tumors with a primary site in the central nervous system have not been reported in literature yet. We report here about a 41-year-old patient with recurrent and progressive low back pain and bilateral S1 radiculopathy on admission. The patient underwent hemi-laminectomies of the vertebral bodies L5 and S1 and an en bloc resection of the tumor. Postoperative histopathological examination resulted in a well-differentiated intrathecal neuroendocrine tumor (carcinoid) of the terminal filum. Postoperative staging showed no pathological abnormalities and no tumor recurrence after 6 months. Even though rare, carcinoids should be considered as differential diagnosis of tumors occurring in the CNS.

Subarachnoid-pleural fistula as a complication of malignant pleural mesothelioma.

We report a 62-year-old male patient with asbestos-related malignant pleural mesothelioma who developed recurrent pleural effusions after surgical resection of paravertebral tumour masses. Pleural effusions were drained on several occasions with the patient suffering severe headaches and vascular dysregulation. Cytological studies of the pleural fluid showed no evidence of inflammatory or malignant cells. The fluid was interpreted as seroma despite its unusual transparency until magnetic resonance imaging was suggestive of a subarachnoid-pleural fistula; its presence was confirmed when beta-trace protein--a specific marker for cerebrospinal fluid--was added to the standard laboratory testing of the pleural effusion. A subarachnoid-pleural fistula has to be included in the differential diagnosis of patients with recurrent pleural effusions after surgical debulkment of malignant pleural mesothelioma. The beta-trace protein may help to establish this diagnosis especially in cases where important therapeutic consequences may need to be drawn.