Fine motor

Figure 10.2. The motor homunculus produced by Penfleld and Rasmussen from direct stimulation studies. Note that the body is distorted and those areas which produce fine motor actions and manipulations (the hand and the mouth) are disproportionately represented.

Ando, K. Johanson, C.E. and Seiden, L.S. Sensitivity changes to dopaminergic agents in fine motor control of rhesus monkeys after repeated methamphetamine administration. Pharmacol Biochem Behav 22 737-743, 1985. 

When finger agnosia was present, there were more errors with the nonpreferred hand (2.05 mean errors) than with the preferred hand (1.88 mean errors). Fewer than 10 percent of the sample showed performances on the hand dynamometer below the normative standards. Conversely, nearly 50 percent of the sample showed below normal performances on the finger oscillation test, a finding that suggests that fine motor dysfunction is more prevalent as a result of PCP and other drug abuse than gross motor dysfunction. 

On NP tests of gross motor activity and fine motor speed, he was mildly impaired in comparison to adult norms. However, he was able to attain normal performance levels with practice and direct encouragement. It is important to note that all other NP tests of sensory, perceptual, and conceptual functions were in the normal range his minimal errors are often made by normal, nonimpaired 1 ndi vidua1s. 

The evaluation results are mildly worrisome however, the quality of the infants behaviors are very worrisome. In the area of fine motor development, the infants performed in the low normal range. Furthermore, the items used to score fine motor behaviors do not identify deviant movements required for the fine motor act. For instance, each of these infants displayed abnormal movement... 

The infants adaptive or playing behaviors with the test objects showed the infants to be spontaneous in their approach to the toys and to demonstrate an interest in manipulating them. Some infants were easily frustrated by their inability to manipulate the objects due to their fine motor difficulties. However, there was no evidence of gross retardation in the emerging cognitive areas. 

As the infants were emerging into a more predictable pattern of behavior, the deviant fine motor movements became apparent. 

Central nervous system maturation progresses in a cephalo-caudal manner, allowing for differentiation of fine motor movements, as those seen in the pincer grasp by 9 months (Gesell et al. 1954). Fair evaluation of the fine motor system was not possible until the last quarter of the first year. 

The observations of fine motor problems in infants born to heroin addicts has also been described by Wilson et al., in 1973. She notes the discrepancy between the gross motor skills of the infants and fine motor abilities during the first year. Furthermore, in 1979, Wilson et al, described the development of preschool children between 3 and 6 years of age, born to heroin-addicted mothers. They performed poorer on measures of visual, tactile, and auditory perception, were more active, and had... 

These findings are in contrast to the developmental outcome of the PCP infants reported in this paper. In spite of the consistent, nurturing environments, these infants have consistently demonstrated borderline abilities in fine motor, adaptive, language and... 

Information from wel1-control 1 ed animal studies that focus on the effects of prenatal exposure to single and polydrug use will be of great value. Further evaluation of the fine motor movements that appear to be clearly neurological ly deviant in the PCP-exposed infants is essential. The emerging socialization skills during the second year of life also need more detailed evaluations. 

Silent" brain lesions on magnetic resonance imaging are associated with poor cognitive and fine motor functions pseudotumor cerebri (case report)... 

A mean Stanford-Binet IQ decrement of 5 points, fine motor dysfunction, and altered behavioral profiles were found in 70 preschool children exhibiting pica for paint and plaster and elevated PbB levels (>40 pg/dL, mean of 58 pg/dL), when compared with results for matched control subjects not engaged in... 

McLaughlin PJ, Delevan CE, Carnicom S, Robinson JK and Brener J (2000). Fine motor control in rats is disrupted by delta-9-tetrahydrocannabinol. Pharmacology, Biochemistry and Behaviour, 66, 803-809. 

Estradiol also induces synapses in the hippocampus and this contributes to enhanced capacity for learning and memory that is dependent on the hippocampus [13]. Estradiol exerts many other nonreproductive actions on the brain, such as fine motor coordination, seizure susceptibility, mood, protection from ischemic damage. Many of these actions occur in brain regions that show little, if any, nuclear estrogen receptors, and it seems likely that the nongenomic estrogen receptor described above may be involved [13]. 

The pons and cerebellum (metencephalon) form the middle portion of the brain stem, bordered rostrally by the midbrain and caudally by the medulla. It also contains a portion of the brain stem and several nuclei important to arousal and sleep. The cerebellum branches off of the back of the brain stem. It has a cortical surface and deep nuclei imbedded in white matter. Through its connections, it has involvement in diverse functions including balance, fine motor coordination, and even cognition. 

In many cells, the capacity for de novo synthesis to supply purines and pyrimidines is insufficient, and the salvage pathway is essential for adequate nucleotide synthesis. In patients with Lesch-Nyhan disease, an enzyme for purine salvage (hypoxanthine guanine phosphoribosyl pyrophosphate transferase, HPRT) is absent. People with this genetic deficiency have CNS deterioration, mental retardation, and spastic cerebral palsy associated with compulsive self-mutilation, Cells in the basal ganglia of the brain (fine motor control) normally have very high HPRT activity. These patients also all have hyperuricemia because purines cannot be salvaged. 

Mercury was used to cure the felt used in hats, and workers developed the characteristic signs of mercury vapor toxicity. Acute exposure to high concentrations of mercury vapor causes respiratory distress, which can be fatal. The symptoms of chronic exposure to mercury vapor include personality changes such as excitability, depression, memory loss, fine motor tremor that can become progressively worse, gingivitis, and hallucination. There is some mercury inhalation exposure from dental amalgam, but for most people there are no health-related effects. Metallic mercury is very poorly absorbed from the intestine, thus it is much better to swallow the mercury from a thermometer than inhale it (see chapter on mercury). 

The most frequent adverse reactions are those that are an extension of the therapeutic effects, i.e. extended CNS depression manifesting itself as distortions in mood and impaired judgment and fine motor skills as well as intellectual performance as long as a day after usage. 

Ethanol readily passes across the placenta and into the fetal circulation. The fetal alcohol syndrome has three primary features microcephaly, prenatal growth deficiency, and short palpebral fissures Other characteristics include postnatal growth deficiency, fine motor dysfunction, cardiac defects, and anomalies of the external genitalia and inner ear. A definite risk of producing fetal abnormalities occurs when ethanol consumption by the mother exceeds 3 oz daily, the equivalent of about six drinks. 

Training for fine motor test Immunophenotyping Clinical pathology Mother-infant interaction Body weight External examination... 

Aged rhesus monkeys were assessed in several cognitive and motor tasks, acquisition of a visual object discrimination, reversal of a visual object discrimination, a delayed response task, a spatial working memory task, and a fine motor task. The S-HTj receptor antagonists ondansetron and SEC-579 at very low oral doses selectively enhanced acquisition of a visual object discrimination task but not the reversal or delayed tasks [Arnsten et al. 1997]. 

In contrast to these reports of benzodiazepine-induced motor impairment, Kumar et al.138 found that chronic administration of 1 mg lorazepam and 0.5 mg alprazolam for 5 days had no effect on fine motor coordination as assessed using a standard pegboard test. Additionally, Tobler et al.139 reported that performance on a typing test was not impaired the day after an acute dose of 7.5 mg midazolam. 

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