Paget disease of bone (PDB) is a chronic skeletal disorder caused by abnormal bone remodeling. Although neurological complications are uncommon, they may arise in advanced cases, particularly with skull involvement.
An 83-year-old woman, who was fully dependent in daily activities, had a history of progressive dementia over several years, characterized by marked loss of short-term memory, decreased spontaneous activity and speech, and apathy. The patient’s neck was short, and her head was markedly enlarged, with a frontal bulge. Radiographs showed an overall enlargement with diploic widening, cotton wool appearance, and the Tam o’ Shanter sign (Figure 1A). Computed tomography showed platybasia with compression of midbrain and pons, along with significant supratentorial ventricular enlargement due to posterior fossa cisterns obstruction and distortion of the Sylvius aqueduct (Figures 1B,C). Bone scintigraphy displayed increased uptake in the facial bones, skull base, and calvarium. Laboratory tests revealed normal levels of calcium (10 mg/dL), phosphate (3.3 mg/dL), alkaline phosphatase (76 IU), procollagen type 1 N-terminal propeptide (48.9 μg/L), and C-terminal telopeptide of type 1 collagen (0.38 μg/L). The patient did not exhibit incontinence, gait ataxia, headaches, or hearing loss.
(A) Lateral radiograph of the skull showing a cotton wool appearance and diploic widening. There is an overall enlargement of the cranium with frontal prominence over the facial bones. This combination, along with associated platybasia, creates the Tam o’ Shanter sign. (B,C) Computed tomography depicting midbrain pons deformity, ventral rectification, and significant supratentorial ventricular enlargement due to obstruction of the posterior fossa cisterns and distortion of the Sylvius aqueduct.
In PDB, skull base softening and flattening can lead to basilar impression, resulting in compression of the brainstem, cerebellum, and fourth ventricle. The consequent reduced posterior fossa volume may cause obstructive hydrocephalus due to blockage of the cisterns and aqueduct.1-3 Given the patient’s advanced dementia and quiescent stage of PDB as evidenced by stable biochemical markers, a decision was made to forgo further treatment. Early diagnosis and management are crucial for preventing further neurological complications.
Footnotes
The authors declare no conflicts of interest relevant to this article. Written informed consent for the publication of the clinical details and any accompanying images was obtained from the patient’s son.
DATA AVAILABILITY
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