High-frequency radio-wave ablation of osteoid osteoma in the lumbar spine

The authors report on the first known application in the spine of percutaneous ablation of osteoid osteoma using radio-frequency waves. The technique involves a CT-guided biopsy of the lesion followed by introduction of a 1-mm probe connected to a radio-frequency lesion generator. The procedure was performed on an outpatient basis and the patient experienced immediate relief of his symptoms. No evidence of recurrence was demonstrated 16 months later. The technique++ described may become the procedure of choice in the surgical treatment of osteoid osteoma, as it minimises surgical trauma and post-operative pain. Longer follow-ups are required to monitor the incidence of recurrence.

Localization of temporal lobe epileptic foci with iodine-123 iododexetimide cholinergic neuroreceptor single-photon emission computed tomography

There is evidence suggesting that muscarinic cholinergic neuroreceptors (mChR) are reduced at seizure foci. Iodine-123 (I-123) iododexetimide (IDEX) single-photon emission computed tomography (SPECT) permits in vivo imaging of mChR. We assessed 23 patients with temporal lobe epilepsy (TLE) undergoing preoperative assessment. Regions of interest were placed over the amygdala, hippocampus, and lateral temporal cortex on IDEX SPECT images. Eighteen patients had unilateral TLE. In these, IDEX binding in the ipsilateral hippocampal region was reduced by 19.1 +/- 12%. This was significantly greater than blood flow asymmetry (p < 0.02 by Wilcoxon's signed-rank test). Changes were less marked in the amygdala (11.3 +/- 6.4%) and lateral cortex (7.6 +/- 12.1%). Blinded visual analysis gave correct localization in 14 (78%) patients, and hexamethylpropylenamine oxide (HMPAO) SPECT gave correct localization in 50%. MRI revealed hippocampal sclerosis in 13 (72%) patients and was normal in 5 patients. Of the latter group, four were correctly localized by IDEX. This study confirms that mChR receptors are altered in medial temporal lobe structures in TLE. IDEX SPECT appears to be superior to interictal HMPAO SPECT and complimentary to MRI for seizure focus localization.

Premature development of erosive osteoarthritis of hands in patients with chronic renal failure

The prevalence of grade III or IV osteoarthritis was determined in 210 patients with chronic renal failure, of whom 94 were receiving chronic haemodialysis and 116 had functioning renal transplants. The prevalence of grade III or IV osteoarthritis was three times greater in patients under 65 than in a control population, and all but two affected patients also had erosion of subchondral bone in at least one affected joint. The excess of osteoarthritis was apparent in both the transplant recipients and those receiving haemodialysis. Over the age of 65 there was no significant difference in prevalence. Metabolic bone disease, including osteopenia, might contribute to the development of erosive osteoarthritis in chronic renal failure.

Is chronic renal failure a risk factor for the development of erosive osteoarthritis?

Erosive osteoarthritis of the hands of unusually early onset and severity was seen in two patients treated for chronic renal failure by long term haemodialysis and renal homograft respectively. The significance of this observation is discussed in the light of previous studies of erosive arthropathy in patients with chronic renal failure. Factors associated with chronic renal failure may predispose to the development of erosive osteoarthritis.