Correlation of right frontal hypoperfusion and urinary dysfunction in iNPH: a SPECT study.
OBJECTIVE
To elucidate the pathophysiology of urinary dysfunction in idiopathic normal-pressure hydrocephalus (iNPH) by single-photon emission computed tomography (SPECT) and statistical brain mapping.


METHODS
Urinary symptoms were observed and N-isopropyl-p-[(123)I]-iodoamphetamine (IMP)-SPECT imaging was performed in 97 patients with clinico-radiologically definite iNPH. The patients included 56 men and 41 women; mean age, 74 years. The statistical difference in normalized mean tracer counts was calculated and visualized between patients with urinary dysfunction of severer degrees (>grade 2/4) and milder degrees (<grade 1/4) according to the urinary subscales of the iNPH grading scales.


RESULTS
There was a significant decrease in tracer activity in the right-side-dominant bilateral frontal cortex and the left inferior temporal gyrus in the severe urinary dysfunction group (P < 0.05). In order to minimize the effects of gait and cognitive dysfunction, we performed similar analysis among subjects with little or no such dysfunction, and obtained the same results (P < 0.05) as described above.


CONCLUSIONS
Urinary dysfunction was found to be closely related with right frontal hypoperfusion in iNPH using [(123) I]-IMP SPECT. This right frontal area is one of the critical areas for regulating micturition. While secondary incontinence can result from gait disturbance or dementia, there may also be a neurogenic mechanism underlying urinary dysfunction, which is a significant burden in patients with iNPH and their caregivers.
Neurology Division, Department of Internal Medicine, Sakura Medical Center, Toho University, Sakura, Japan. sakakibara@sakura.med.toho-u.ac.jp
Ryuji
R
Sakakibara
Yoshitaka
Y
Uchida
Kazunari
K
Ishii
Hiromitsu
H
Kazui
Masaaki
M
Hashimoto
Masaaki
M
Ishikawa
Tatsuhiko
T
Yuasa
Masahiko
M
Kishi
Emina
E
Ogawa
Fuyuki
F
Tateno
Tomoyuki
T
Uchiyama
Tatsuya
T
Yamamoto
Tomonori
T
Yamanishi
Hitoshi
H
Terada
D000368:Aged; D000369:Aged, 80 and over; D001931:Brain Mapping; D003072:Cognition Disorders / Q000503:physiopathology; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D020233:Gait Disorders, Neurologic / Q000503:physiopathology; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000150:complications* / Q000503:physiopathology; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow / Q000502:physiology*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D015899:Tomography, Emission-Computed, Single-Photon; D014549:Urinary Incontinence / Q000453:epidemiology* / Q000503:physiopathology; D014555:Urination Disorders / Q000453:epidemiology* / Q000503:physiopathology
D007457:Iodine Radioisotopes