Dissociated effects of quiet stance on standard and high-frequency (600 Hz) lower limb somatosensory evoked potentials.

OBJECTIVE: To verify whether standing can modulate somatosensory input from lower limb to the cortex. Somatosensory afferents have been evaluated not only by means of somatosensory evoked potentials recorded by means of classical wide-bandpass filtering (standard SEPs), but also by high-frequency somatosensory evoked potentials (HF-SEPs), which probably play a role in the processing of rapid adaptive changes. METHODS: Eight healthy subjects underwent right posterior tibial nerve (PTN) stimulation in two different conditions (standing and lying supine). Standard SEPs reflecting the activity of both subcortical and cortical generators further underwent digital filtering (300-800 Hz), in order to enhance HF-SEP components. RESULTS: Stance significantly reduces the P40 cortical component of standard SEPs. By contrast, HF-SEPs did not show any significant change between the two conditions. CONCLUSIONS: The lack of any gating effect on HF-SEPs lends further substance to the hypothesis that HF-SEPs play a pivotal role in the processing of somatosensory inputs related to rapid adaptive changes. SIGNIFICANCE: Our data confirm that standard and HF-SEPs reflect two distinct mechanisms with strongly different functional significance. Further studies are needed to definitively establish whether this dissociation is merely caused by the activation of anatomically different neuronal pools, or by the involvement of distinct functional mechanisms.

Cognitive functions and elderly cancer patients receiving anticancer treatment: a prospective study.

It has been reported that anticancer treatment may cause cognitive impairment. Elderly patients in particular could be at increased risk for treatment-related cognitive deterioration. A consecutive series of cancer out-patients >or=65 years old were prospectively assessed by means of a neuropsychological test Cambridge Cognitive Examination (CAMCOG) test at baseline, and after 3 and 6 months from study entry. Patients were categorized in three groups (group 1, no anticancer treatment; group 2, receiving chemotherapy; group 3, receiving endocrine therapy). Comprehensive geriatric assessment was performed at the three time points evaluation. Sixty-one patients were enrolled (32, 16 and 13, in groups 1, 2, and 3, respectively). At baseline, cognitive function was directly correlated to Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL) scores and was associated with higher educational level and absence of depression. Overall, cognitive function did not worsen across time in each group. However, more patients in the CT group showed worsening in memory skills, and more patients in the ET and CT group experienced reduction in the attention score.