Phantom touch: How to unmask sensory unawareness after stroke.

Comprehending the nature of tactile disorders following brain damage is crucial to understand how the brain constructs sensory awareness. Stroke patients may be unaware of being touched on the affected hand if, simultaneously, they are touched on the unaffected hand (i.e., tactile extinction). More rarely, they feel touches on the two hands, when they are solely touched on the unaffected hand (i.e., synchiria). Using a novel assessment tool, we investigated whether in stroke patients with apparent intact tactile awareness on standard evaluation, tactile extinction might be possibly masked by phantom (synchiric) sensations (i.e., elicited by ipsilesional stimulation) arising exclusively during Double Simultaneous Stimulation (DSS). Patients with right (n = 17) and left (n = 8) hemisphere lesions and age-matched healthy controls (n = 13) were tested with the Tactile Quadrant Stimulation test, consisting in delivering unilateral or bilateral touches to one of four quadrants, identified on the participants' hands. In DSS trials, stimuli were applied to asymmetric quadrants. Participants reported the side(s) and then pointed to the site(s) of stimulation. We found that, with the exception of one patient who showed tactile extinction, about 50% of patients with overall intact tactile perception on classical evaluation, although reporting two stimuli in DSS, failed in pointing to the correct contralesional stimulated site. They reported the felt sensation in positions that corresponded to the ipsilesional stimulated sites. Thus apparent detections of contralesional touches in DSS were accounted for by 'phantom' sensations of ipsilesional stimulation that masked unawareness of contralesional touches when classic assessment was applied. Preliminary lesion analyses indicate that the symptom was associated with damage to structures often affected in tactile extinction. These findings, while unveiling important underestimation of the patients' neurological condition, provide a framework for investigating bihemispheric contributions to altered tactile perception following stroke.

Sexual Well-Being in Patients with Blepharospasm, Spasmodic Torticollis, and Hemifacial Spasm: A Pilot Study.

Mood, anxiety, and other psychological symptoms are common in dystonic patients suffering from blepharospasm (BSP) and spasmodic torticollis (ST). Since sexual well-being is an important aspect of mental health, here, we investigated whether these patients may also experience a worsening of their sexual life. In particular, quality of sexual life was evaluated in patients suffering from BSP (N = 30), ST (N = 30), and in a control group of patient with Hemifacial spasm (HFS; N = 30), undergoing botulinum toxin type A therapy. A group of 30 age-matched healthy volunteers constituted an additional control group. Patients were evaluated just before the periodic injection of botulinum toxin. Sexual functioning was assessed using the Sexual Functioning Inventory, a reduced form of the Golombok Rust Inventory, previously employed in patients with Parkinson's disease. Depression (Beck Depression Inventory) and anxiety (STAI-X1/X2) were also assessed. Results revealed that sexual functioning was significantly affected in patients with BSP, ST, and HFS with respect to healthy controls. Dystonic patients manifested more sexual dysfunction than patients with HFS. Overall, females had a poorer quality of sexual life than males and, among females, women with BSP were the most dysfunctional. Psychological symptoms were present in patients with dystonia, but not in patients with HFS. As discussed in the paper, several factors might be taken into account to explain worse quality of sexual life in patients with dystonia compared to patients with hemifacial spasm. Among them an important role might be played by the central origin of dystonia pathophysiology (i.e., altered activity of cortico-striato-thalamic-cortical circuits). Future investigations are necessary to further explore these preliminary findings, considering that this is the first time that sexual well-being is evaluated in patients with BSP, ST, and HFS, and comparable data are not available.

Unseen facial and bodily expressions trigger fast emotional reactions.

The spontaneous tendency to synchronize our facial expressions with those of others is often termed emotional contagion. It is unclear, however, whether emotional contagion depends on visual awareness of the eliciting stimulus and which processes underlie the unfolding of expressive reactions in the observer. It has been suggested either that emotional contagion is driven by motor imitation (i.e., mimicry), or that it is one observable aspect of the emotional state arising when we see the corresponding emotion in others. Emotional contagion reactions to different classes of consciously seen and "unseen" stimuli were compared by presenting pictures of facial or bodily expressions either to the intact or blind visual field of two patients with unilateral destruction of the visual cortex and ensuing phenomenal blindness. Facial reactions were recorded using electromyography, and arousal responses were measured with pupil dilatation. Passive exposure to unseen expressions evoked faster facial reactions and higher arousal compared with seen stimuli, therefore indicating that emotional contagion occurs also when the triggering stimulus cannot be consciously perceived because of cortical blindness. Furthermore, stimuli that are very different in their visual characteristics, such as facial and bodily gestures, induced highly similar expressive responses. This shows that the patients did not simply imitate the motor pattern observed in the stimuli, but resonated to their affective meaning. Emotional contagion thus represents an instance of truly affective reactions that may be mediated by visual pathways of old evolutionary origin bypassing cortical vision while still providing a cornerstone for emotion communication and affect sharing.

Does subthalamic stimulation induce personality modifications in Parkinson's disease? A Rorschach Test explorative study.

The aim of this study was to investigate personality, by means of the Rorschach Psychodiagnostic test, in a consecutive series of fourteen patients with Parkinson's disease (PD) submitted to bilateral deep brain stimulation of the subthalamic nucleus (DBS STN). Patients were evaluated pre-operatively and 1 year after surgery. Patients were also assessed for motor disability and cognitive status. All the patients obtained a significant amelioration of motor symptoms and could reduce the dopaminergic treatment after surgery. No cognitive decline was observed comparing the pre- to the post-operative neuropsychological assessment. The comparison between pre- and post-operative Rorschach indexes showed no major modifications of personality structure. The results of the present explorative study suggest that DBS of STN does not result in relevant personality modifications in patients with Parkinson's disease.

Temporal changes in movement time during the switch of the stimulators in Parkinson's disease patients treated by subthalamic nucleus stimulation.

OBJECTIVE: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a very effective therapy for the advanced phase of Parkinson's disease (PD). The functional inhibition of this nucleus is responsible for a significant improvement of cardinal motor symptoms of PD. The aim of the study was the assessment of the effectiveness of STN DBS on bradykinesia by the analysis of movement time (MT) in 2 conditions: with the stimulators turned on ('stim-on') or off ('stim-off'). METHODS: After pharmacological wash-out, 10 patients submitted to bilateral STN DBS were studied with an MT analyser in 3 phases: stim-on, stim-off and stim-on again, in order to establish the time course of MT lengthening, the posteffect duration and the latency of the effect of STN DBS. MT data were then compared with the UPDRS motor scores. RESULTS: After turning off the stimulators, MT progressively increases, reaching a plateau after about 30 min, which then lasts for the subsequent observation time (2 h). A significant elongation is achieved after the first 5 min. Upon pulse generator activation, MT shows a dramatic shortening, already significant after 2 min. Moreover, we observed a significant correlation between MT and the severity of PD, higher with bradykinesia than with rigidity or tremor. CONCLUSION: Our findings show a relevant effect of STN DBS on MT, a parameter strongly related to bradykinesia. This study confirms the effectiveness of STN inhibition on the whole parkinsonian triad, suggesting that this target can be considered a proper choice for the surgical treatment of advanced PD.

Deep brain stimulation of the subthalamic nucleus in PD: an analysis of the exclusion causes.

OBJECTIVE: Deep Brain Stimulation (DBS) of the Subthalamic Nucleus (STN) represents a proper choice for the treatment of advanced Parkinson's disease (PD). A correct selection of the patients as candidates for the surgery is essential for a good outcome. In this study, we analyzed the exclusion causes of a series of PD patients hospitalized for the selection protocol. METHODS: Ninety-eight PD patients as potential candidates for the STN DBS were studied. All patients were hospitalized and underwent a clinical evaluation of the PD stage, a levodopa challenge, a MR of the brain and a neuropsychological assessment. RESULTS: The percentage of subjects considered not suitable for the surgery was 29.6%. A single cause of exclusion was present in 65.5% of not suitable patients, while multiple causes were present in 34.5%. The most frequent cause of exclusion was the finding of neuropsychological or psychic disorders (48.3%); in 37.9% of the patients, the motor disability was not severe enough to justify the surgery, while in 31%, we found relevant abnormalities at the brain MR. Three patients (10.3%) were poorly motivated for the surgery, while in three others (10.3%), we found a significant illness other than PD. CONCLUSIONS: The finding that about 30% of the PD patients potentially suitable for STN DBS presents some exclusion causes underlines the importance of a careful selection of the candidates for this surgery.