Postural imbalance and falls in PSP correlate with functional pathology of the thalamus.

OBJECTIVE: To determine how postural imbalance and falls are related to regional cerebral glucose metabolism (PET) and functional activation of the cerebral postural network (fMRI) in patients with progressive supranuclear palsy (PSP). METHODS: Sixteen patients with PSP, who had self-monitored their frequency of falls, underwent a standardized clinical assessment, posturographic measurement of balance during modified sensory input, and a resting [¹8F]FDG-PET. In addition, patients performed an fMRI paradigm using mental imagery of standing. Results were compared to healthy controls (n = 16). RESULTS: The frequency of falls/month in patients (range 1-40) correlated with total PSP rating score (r = 0.90). Total sway path in PSP significantly correlated with frequency of falls, especially during modulated sensory input (eyes open: r = 0.62, eyes closed: r = 0.67, eyes open/head extended: r = 0.84, eyes open/foam-padded platform: r = 0.87). Higher sway path values and frequency of falls were associated with decreased regional glucose metabolism (rCGM) in the thalamus (sway path: r = -0.80, falls: r = -0.64) and increased rCGM in the precentral gyrus (sway path: r = 0.79, falls: r = 0.64). Mental imagery of standing during fMRI revealed a reduced activation of the mesencephalic brainstem tegmentum and the thalamus in patients with postural imbalance and falls. CONCLUSIONS: The new and clinically relevant finding of this study is that imbalance and falls in PSP are closely associated with thalamic dysfunction. Deficits in thalamic postural control get most evident when balance is assessed during modified sensory input. The results are consistent with the hypothesis that reduced thalamic activation via the ascending brainstem projections may cause postural imbalance in PSP.

[Reduced bone density and bone pain :osteomalacia with hypophospatemia and hypophosphaturia]. / Erniedrigte Knochendichte und Knochenschmerzen : Osteomalazie mit Hypophosphatämie und Hyperphosphaturie.

Two patients aged 24 and 64 years presented at our hospital with similar symptoms including bone pain and muscle weakness. Basic laboratory tests and urinary diagnostics, bone densitometry and bone histology revealed severe osteomalacia with renal phosphate wasting. After the exclusion of other causes an extensive tumor search was performed due to suspected tumor-induced osteomalacia. In one patient a mesenchymal tumor was found in the thigh and completely resected. After surgery the patient showed a rapid recovery from osteomalacia. Because the search was unsuccessful in the other patient phosphorus supplementation in combination with calcitriol was started. Despite continuing renal phosphate wasting a significant increase in bone mineral density was observed.