Evidence by functional imaging studies suggests the role of left dorsolateral prefrontal cortex (DLPFC) in the inhibitory control of nociceptive transmission system. Repetitive transcranial magnetic stimulation (rTMS) is able to modulate pain response to capsaicin. In the present study, we evaluated the effect of DLPFC activation (through rTMS) on nociceptive control in a model of capsaicin-induced pain. The study was performed on healthy subjects that underwent capsaicin application on right or left hand. Subjects judged the pain induced by capsaicin through a 0–100 VAS scale before and after 5 Hz rTMS over left and right DLPFC at 10 or 20 min after capsaicin application in two separate groups (8 subjects each). Left DLPFC-rTMS delivered either at 10 and 20 min after capsaicin application significantly decreased spontaneous pain in both hands. Right DLPFC rTMS showed no significant effect on pain measures. According to these results, stimulation of left DLPFC seems able to exert a bilateral control on pain system, supporting the critical antinociceptive role of such area. This could open new perspectives to non-invasive brain stimulation protocols of alternative target area for pain treatment.

Subtle clinical cerebellar alterations have been found in migraine. Moreover, abnormalities in visual and motor cortex excitability consistent with a lack of inhibitory efficiency have been described in migraine, and it is known that cerebellum exerts an inhibitory control on cerebral cortex. Here, we investigated if impairment of cerebellar activity on motor cortex, i.e. reduced inhibitory control, can be found in migraine. Ten migraineurs with aura and seven healthy controls underwent a transcranial magnetic stimulation (TMS) protocol to investigate the cerebellar inhibitory drive on motor cortex: a conditioning pulse on right cerebellar cortex was delivered 5, 7, 10, 15 ms before a test stimulus (TS) on contralateral motor cortex. The cerebellar conditioning stimulus inhibits the size of the motor-evoked potential (MEP) produced by the TS alone by approximately 30-50%. Amplitude of MEP to TS alone showed no significant difference between patients and controls. Cerebellar conditioning TMS showed a significant deficit of cerebellar inhibition in migraine patients as compared to controls at all interstimulus intervals (5-15 ms) tested. Cerebellar inhibition is reduced in migraineurs. This could account, at least in part, for the reduced inhibitory efficiency previously showed in cerebral cortex of these patients.

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Previous studies of auditory hallucinations in schizophrenia found that the hallucinations were reduced by the application of transcranial magnetic stimulation (rTMS). Here we describe a case of traumatic brain injury associated with continuous music hallucinations. An MRI scan showed a structural lesion of the right temporal pole and a PET scan indicated a hyperactive area of the posterior right temporal lobe. We hypothesized that rTMS applied to the right temporal area would reduce this activity and the corresponding hallucinations. The patient's music hallucinations were significantly reduced by rTMS treatment. A PET scan following treatment also indicated that rTMS treatment reduced brain activity in the right temporal lobe. This case provides initial evidence that rTMS may be a successful treatment of syndromes associated with hyperactive brain areas.

Chloroform is a recognised cause of acute liver injury, although now rarely encountered in clinical practice. We present a case of inhalational chloroform self-poisoning in a 47-year-old man that presented to hospital initially with reduced conscious level and later developed acute liver injury that was treated with intravenous acetylcysteine. This paper reviews the existing literature and presents a summary of the mechanisms of chloroform hepatotoxicity. Published cases show that there is a characteristic delay of 24 to 48 hours between chloroform exposure and elevation of liver transaminase activity. Therefore, clinicians need to provide an appropriate duration of monitoring in order to detect the occurrence of this important toxic effect.