Frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) is characterised clinically by dominantly inherited cognitive decline, behavioural changes and motor impairment Reference Foster, Wilhelmsen, Sima, Jones, D'Amato and Gilman(1). Herein, we report a patient with FTDP-17 who presented with prominent hemispatial neglect, a syndrome that has not been reported in previous studies.
A 58-year-old right-handed man was diagnosed with FTDP-17 and a subsequent sequence analysis revealed a P301L mutation in the tau gene (MAPT). He had a 10-year history of apathy and behavioural disturbances and developed left-sided parkinsonism after seven years. Rigidity and tremor were initially levodopa-responsive. Neurological assessment revealed left-sided rigidity and postural tremor, vertical nystagmus and primitive reflexes. Electroencephalography was normal. Head magnetic resonance imaging showed a right temporal lobe atrophy with temporal horn enlargement. Cerebral blood flow measured by rCBF SPECT with 99 mTc-ECD showed right hypoperfusion of the frontal lobe (52–68% of cerebellar perfusion), inferior and anterior parts of the right temporal lobe and posterior parietal lobe including the parieto-occipital area.
On initial neuropsychological examination performed 10 years after symptomatic disease onset, the patient displayed severe executive deficits with disinhibition and echopraxis, suggestive of atypical subcortical dementia. Over the following 6-month period, global cognitive function assessed with the Mini Mental State Examination Reference Folstein, Folstein and McHugh(2) declined from 28/30 to 24/30. He scored 82/100 on the revised version of the Addenbrooke's Cognitive Examination (ACE-R) Reference Mioshi, Dawson and Mitchell(3) and 98/144 on the Mattis Dementia Rating Scale Reference Mattis, Bellack and Karasu(4). A unilateral neglect syndrome was suspected based on a history of left-sided neglect during bathing, shaving and dressing, and on lateralised abnormalities observed when performing the clock-drawing test from ACE-R (Fig. 1). Subsequently, a comprehensive neglect-oriented test battery was administered, which consistently indicated unilateral neglect.
Fig. 1 Clock drawing task from ACE-R Reference Mioshi, Dawson and Mitchell(3).
The Schenkenberg test revealed a significant 6.77 mm deviation to the right on average. Abnormalities were also observed using a visual search trial Reference Wieczorek and Jodzio(5), during which 20 target objects are put in the centre of a rectangular board, one at a time. Each time, the patient is instructed to identify the same object as the target as quickly as possible. Additional targets are randomly distributed in all four quadrants (five in each quadrant). The longest reaction times occurred in the upper left quadrant (mean = 42 s), similar reaction times in the lower left and upper right quadrants (mean = 16 s and 18 s respectively), and the shortest reaction times for the lower right quadrant (mean = 9 s). In a letter cancellation task from the Behavioral Inattention Test, he made three omission errors in the first, second and third columns. In the scattered letter cancellation task, he made five omission errors in the left lower quadrant and two omission errors in the left upper quadrant. In all paper-pencil tasks, reversed order of execution (from the right side to the left) was observed. The Functional Neglect Assessment Battery (FNAS) Reference Wieczorek and Jodzio(5) was administered to assess the impact of neglect symptoms on daily life function. The FNAS battery includes tasks referring to personal space (e.g. shaving, using a comb and putting on gloves and glasses) and peripersonal space (e.g. dealing cards, laying the table and scanning a newspaper in search of symmetrically distributed headlines). Results showed significant impact of symptoms in the category of personal space. In writing a short dictated text, the patient had a slight tendency to neglect the left side of the paper. There was a progressive deviation of the text to the right. In a reading task, only one word on the left was omitted.
Hemispatial neglect has occasionally been reported in patients with frontotemporal dementia, particularly those with corticobasal degeneration (CBD) (Reference Mitani, Uchihara, Tamaru, Endo and Tsukagoshi6–Reference Nagaoka, Ookawa and Maeda9); however, it has not been highlighted in FTDP-17. As observed in CBD, our patient presented with neglect on the left side associated with contra-lateral brain atrophy and hypoperfusion (Reference Mitani, Uchihara, Tamaru, Endo and Tsukagoshi6,Reference Kleiner-Fisman, Black and Lang8,Reference Nagaoka, Ookawa and Maeda9). Neglect in our patient was more pronounced in personal space and less evident in peripersonal space, in contrast with most common clinical observations Reference Robertson, Halligan, Robertson and Halligan(10).
This report shows that unilateral neglect symptoms may affect the results of cognitive tests that focus on executive dysfunction and utilise visuospatial components (like the maze or tower tasks). Moreover, asymmetrical neglect of personal hygiene in FTDP-17 patients may stem from hemispatial dysfunction, and should not be interpreted as a psychiatric symptom. We therefore suggest that patients diagnosed with FTDP-17 should undergo testing for unilateral neglect, especially if right-sided asymmetry is observed on neuroimaging.
