Abnormal skull uptake on bone scan

Management of Hydrocephalus in Paget's Disease of Bone: Systematic Review and Illustrative Case

OBJECTIVE

Paget's disease of the bone (PDB) is a focal bone disorder characterized by excessive resorption and deposition of pathologic bone. It can involve the skull and cause neurologic dysfunction. Hydrocephalus occurring as a complication has also been reported. However, owing to its rarity, the optimal treatment has not yet been determined.

METHODS

We report the case of a 60-year-old woman with a diagnosis of PDB who had presented with symptomatic hydrocephalus and was successfully treated with ventriculoperitoneal shunt insertion. We also performed a systematic review of the Scopus and PubMed databases for case reports and series documenting patients with PDB complicated by hydrocephalus and discussed the clinical features and therapeutic strategies used.

RESULTS

We found 28 cases of PDB complicated by hydrocephalus in reported studies, including the present case. The median age was 67 years (range, 48-85 years; interquartile range, 7 years), with a female sex predilection. The most common neurologic manifestations were cognitive impairment, gait unsteadiness, urinary incontinence, hearing loss, and headache. Surgery had been performed in 73% of the 28 cases. The most common operation was insertion of a ventriculoperitoneal shunt (63.2%). Cerebrospinal fluid diversion resulted in significant or complete neurologic recovery in 78.9% of the 28 patients. Posterior fossa decompression was performed in 15.8% of operative cases but did not significantly alter the clinical course.

CONCLUSION

Patients with hydrocephalus occurring as a complication of PDB will most commonly present with cognitive impairment, gait unsteadiness, and urinary incontinence. Surgery plays an important role in the treatment, with CSF diversion procedures resulting in significant neurologic recovery in most cases.

Bone scans, bisphosphonates, and a lack of acute changes within the mandible

PURPOSE

The etiology of osteonecrosis of the jaw is poorly understood, but preferential mandibular uptake of intravenous bisphosphonates (IVBPs) has been implicated. We examined this association within a prospective study assessing the effect of IVBPs on radionuclide bone scanning.

PATIENTS AND METHODS

Women with at least 3 osseous breast metastases on bone scanning and previous IVBP use within 8 weeks were eligible for the present study. After the first clinically indicated bone scan, the patients received zoledronic acid within 72 hours and underwent a second bone scan within another 72 hours. The regions of interest on the bone scan were read in triplicate, and the mean count per pixel was calculated for the mandible (C(M)), left femur (C(FL)), right femur (C(FR)), and thigh (C(B)). The mandibular bone turnover (MBT) was quantified as the ratio of (C(M) - C(B))/(C(F) - C(B)), where C(F) = (C(FL) + C(FR)/2). The MBT was compared before and after IVBP use.

RESULTS

A total of 10 patients were enrolled (median age 51 years, range 40 to 71); none had known osteonecrosis of the jaw. Of the 10 patients, 8 had paired bone scans available for analysis. The previous zoledronic acid exposure was 48.6 mg (range 24 to 148) for a median of 13 months (range 6 to 35). The baseline mean MBT ratio was 2.33 (range 0.88 to 4.22). After IVBP administration, the mean MBT ratio was statistically unchanged at 2.23 (range 1.05 to 3.09). The MBT had declined in 4 patients and increased in 4. Only 1 patient had had an MBT of less than 1.0 before IVBP use, and no patient had an MBT ratio of less than 1.0 after IVBP use.

CONCLUSIONS

The mandibular region appears to be a site of increased uptake of technetium-99m bound to methylene diphosphonate-technetium. Acute changes in bisphosphonate binding in the mandible were not observed in our patients receiving chronic IVBP therapy.