Preventive Gabapentin versus Pregabalin to Decrease Postoperative Pain after Lumbar Microdiscectomy: A Randomized Controlled Trial

STUDY DESIGN: Randomized controlled trial. PURPOSE: The purpose of this study was to compare pregabalin and gabapentin for mean postoperative visual analog score (VAS) for pain in patients undergoing single-level lumbar microdiscectomy for intervertebral disc prolapse at a tertiary care hospital. OVERVIEW OF LITERATURE: Pregabalin has a superior pharmacokinetic profile and analgesic effect at lower doses than gabapentin; however, analgesic efficacy must be established during the perioperative period after lumbar spine surgery. METHODS: This randomized controlled trial was carried out at our institute from February to October 2011 on 78 patients, with 39 participants in each study group. Patients undergoing lumbar microdiscectomy were randomized to group A (gabapentin) or group B (pregabalin) and started on trial medicines one week before surgery. The VAS for pain was recorded at 24 hours and one week postoperatively. RESULTS: Both groups had similar baseline variables, with mean ages of 42 and 39 years in groups A and B, respectively, and a majority of male patients in each group. The mean VAS values for pain at 24 hours for gabapentin vs. pregabalin were comparable (1.97±0.84 vs. 1.6±0.87, respectively; p=0.087) as were the results at one week after surgery (0.27±0.45 vs. 0.3±0.46, respectively; p=0.79). None of the patients required additional analgesia postoperatively. After adjusting for age and sex, the VAS value for group B patients was 0.028 points lower than for group A patients, but this difference was not statistically significant (p=0.817, R²=0.018). CONCLUSIONS: Pregabalin is equivalent to gabapentin for the relief of postoperative pain at a lower dose in patients undergoing lumbar microdiscectomy. Therefore, other factors, such as dose, frequency, cost, pharmacokinetics, and side effects of these medicines, should be taken into account whenever it is prescribed.

Variation in Outcome in Tethered Cord Syndrome

STUDY DESIGN: Fifty patients surgically treated for tethered cord syndrome (TCS) were retrospectively studied at Liaquat National Hospital, Karachi from 2010 until 2014. PURPOSE: To assess the common presentations of TCS in our part of the world and the surgical outcome of the different presentations. OVERVIEW OF LITERATURE: TCS is a stretch-induced functional disorder of the spinal cord with its caudal part anchored by an inelastic structure, which results in characteristic symptoms and signs. Due to the variety of lesions and clinical presentations and the absence of high-quality clinical outcome data, the decision regarding treatment is difficult. METHODS: Fifty consecutive patients with TCS were reviewed retrospectively with a follow-up period of 12–48 months. The majority of the patients were 0-15 years of age with the mean age of 4 years. The presenting complaints and the associated pathologies were documented, and the patients were assessed using the new Karachi TCS severity scale for clinical assessment. RESULTS: Eighty five percent of the patients with thickened filum terminale improved. Sixty six percent of the patients with diastematomyelia, 60% with lipoma and only 46% with myelomeningocele showed clinical improvement postoperatively. Sixty two percent of the patients who presented with paraperesis improved following surgery while 37% remained stable and only one patient deteriorated. Back and leg pain improved in 93% of patients and 50% of patients with urinary impairment improved. CONCLUSIONS: Outcome of patients with TCS varies according to pathology and severity of symptoms. Diastematomyelia and thickened filum had the best outcome. The Karachi TCS severity scale is a valid tool for future studies.

Computed Tomography-Guided Biopsy for Potts Disease: An Institutional Experience from an Endemic Developing Country

STUDY DESIGN: A retrospective chart review. PURPOSE: In endemic resource poor countries like Pakistan, most patients are diagnosed and treated for Potts disease on clinical and radiological grounds without a routine biopsy. The purpose of this study was to evaluate the use and effect of computed tomography (CT)-guided biopsy in the management of Potts disease since the technique is becoming increasingly available. OVERVIEW OF LITERATURE: CT-guided biopsy of spinal lesions is routinely performed. Literature on the utility of the technique in endemic resource poor countries is little. METHODS: This study was conducted at the Neurosurgery section of Aga Khan University Hospital Karachi. All the patients with suspected Potts disease who underwent CT-guided biopsy during the 7 year period from 2007 to 2013 were included in this study. Details of the procedure, histopathology and microbiology were recorded. RESULTS: One hundred and seventy-eight patients were treated for suspected Potts disease during the study period. CT-guided biopsies of the spinal lesions were performed in 91 patients (51.12%). Of the 91 procedures, 22 (24.2%) were inconclusive because of inadequate sample (10), normal tissue (6) or reactive tissue (6). Sixty-nine biopsies were positive (75.8%). Granulomatous inflammation was seen in 58 patients (84.05%), positive acid-fast bacillus (AFB) smear in 4 (5.7%) and positive AFB culture in 12 patients (17.3%). All 91 cases in which CT-guided biopsy was performed responded positively to antituberculosis therapy (ATT). CONCLUSIONS: 75.8% of the specimens yielded positive diagnoses. Granulomatous inflammation on histopathology was the commonest diagnostic feature. In this series, the rates of positive AFB smear and culture were low compared to previous literature.