Task-specific tremor diagnoses remain controversial. We evaluated 56 subjects seen with writing tremor. The diagnosis was made if there was a clear history of exclusive tremor while writing for at least 3 years before noticing tremor in any other scenario and the continued presence of writing tremor as the most prominent aspect of their tremor disorder on examination. The age of tremor onset was 47.2 ± 18.0 years (73.2% male). Ethnic backgrounds were Caucasian (68.4%), African (23.2%), Hispanic (5.2%), and Asian/Indian (3.3%), and 44% reported any tremor in a first degree relative. Writing tremor often progressed to other task-specific tremors or rest tremor but not to immediate postural tremor, as usually seen in essential tremor. The other tremor provoking scenarios were eating/drinking (14), brushing teeth/shaving/make-up (5), typing (2), suture removal (1), and drafting (1) and occurred a mean of 7.5 years after the onset of writing tremor. Fourteen developed a "rest" (true rest or crescendo) tremor but only 2 of these met clinical criteria for Parkinson's disease. Pharmacologic treatments of writing tremor, including with ethanol, were generally poor, whereas deep brain stimulation of the ventral intermediate (VIM) thalamus was successful. Compared with patients with "classic" essential tremor in our clinic, writing tremor patients were more likely African, more likely male, had an older age of onset, a lower likelihood of familial tremor, and were more refractory to tremor medications and ethanol. This supports segregation between task-specific tremor and essential tremor but does not support the specific diagnosis of "writing tremor" because many patients progress to tremor with other tasks.

Micrographia is a common, often presenting feature of Parkinson's disease. We assessed a simple writing paradigm in 40 PD patients "off" medications, 40 different PD patients "on" medications, and 64 age- and sex-matched controls. Patients wrote "Today is a nice day" with both eyes open and eyes closed to assess the effects of visual withdrawal (eyes closure). The order (eyes open vs. eyes closed) was alternated. In the "off" medicine group, eye closure increased the writing length by 14.0 +/- 10.1% (P < 0.05) from a mean of 69.1 to 77.7 mm [range -14% to +73%]. The percentage increase was larger in the 20 subjects with the smallest baseline writing size (worse micrographia), compared to the 20 with relatively larger writing (19.5% vs. 7.9%, P < 0.05). Neither the "on" medicine group, nor the control group changed. Simple eye closure significantly increased writing size in "off" PD patients to a similar or greater amount as levodopa. This data suggests that micrographia is not a pure motor hypokinetic feature but is affected by PD similar to other superlearned tasks such as walking. Furthermore, some patients have adapted this simple eye closing strategy when writing, especially signatures.

Restless legs syndrome (RLS) is clinically defined by the presence of (i) an urge to move the legs with or without an actual paraesthesia; (ii) a worsening of symptoms with inactivity; (iii) improvement with activity; and (iv) a worsening of symptoms in the evening and at night. Patients may use a variety of semantic phrases to describe their symptoms but all must have an urge to move. Most people with RLS also have periodic limb movements during sleep, although this is not part of the clinical diagnostic criteria. RLS is very common. About 10% of all Caucasian populations have RLS, although it may be mild in the majority of cases. Women generally outnumber men by about 2:1. As a general rule, RLS severity worsens through the first seven to eight decades of life, but may actually lessen in old age. The aetiology of RLS is only partly understood. There is a strong genetic component, and several genetic linkages and three causative genes have been identified worldwide. Several medical conditions, including renal failure, systemic iron deficiency and pregnancy, and possibly neuropathy, essential tremor and some genetic ataxias, are also associated with high rates of RLS. In all cases to date, the actual CNS pathology of RLS demonstrates reduced iron stores, in a pattern that suggests that the homeostatic control of iron is altered, not just that there is not enough iron entering the brain. The relationship between reduced CNS iron levels and the clinical phenotype or treatment response to dopaminergics is not known but generates promising speculation. Treatment of RLS is usually rewarding. Most patients respond robustly to dopamine receptor agonists. Over time, response may lessen, or the patients may develop 'augmentation', whereby they have a worsening of symptoms, usually in the form of an earlier onset. Other treatment options include gabapentin, or similar antiepileptic drugs, and opioids. High-dose intravenous iron is a promising but still experimental approach.

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BACKGROUND: Peripheral nerve stimulation (PNS) is an effective alternative for the management of neuropathic peripheral chronic pain, but the high incidence of adverse events such as lead and battery erosion, migration, lead fracture, disconnection, and infection have limited the widespread use of PNS. Neuromodulation technology that does not include implantable pulse generators (IPGs) but a 4- or 8-contact electrode array with embedded electronics and a small, externally worn rechargeable transmitter reduces the complications related to the implant of an IPG. PNS has traditionally been performed with a tonic stimulation protocol. This case series describes a wireless PNS device at subthreshold frequencies for the treatment of neuropathic pain of peripheral nerve origins. CASE REPORT: No adverse events were reported, and no complications were encountered during implantation. All patients reported more than 50% pain relief during the one-week trial period, sustained pain relief with various placements and number of electrodes, and an important improvement in quality of life and sleep. Mean VAS scores decreased 78% at one month (n = 11) and remained stable at 6 months with 91% reduction (n = 5) and 76% reduction (n = 1) at 12 months. Mean PGIC at 6 months was 7 of 7. CONCLUSION: Percutaneous placement of an externally powered neurostimulation device adjacent to the affected peripheral nerve(s) is an effective, minimally invasive, and reversible method of pain control in patients with neuropathic pain. PNS using subthreshold frequencies effectively controls neuropathic pain from multiple peripheral nerve targets. KEY WORDS: High frequency, peripheral nerve stimulation, peripheral neuropathic pain, externally powered