Application of a wearable switch to perform a mouse left click for a child with mix type of cerebral palsy: a single case study

Abstract

Purpose: Children with cerebral palsy may face difficulties using handheld pointing devices, due to involuntary muscle movements. This study aimed at describing the idea of the new wearable sensor switch and assessing its feasibility as an access solution in a case of mixed-type cerebral palsy.

Methods: The study participant was a 17-year-old male with mixed-type cerebral palsy characterized by chorea-athetotic movements and bilateral spasticity with gross motor function classification system level V. He exhibited sudden and irregular involuntary upper limb movements when sitting. Because spastic finger movements limited his ability to use a handheld mouse, he used a trackball near his neck as a pointing device (previous input method). The wearable switch system using a stretchable strain sensor was introduced; the sensor was attached to a groove worn on the dorsal regions of the right hand crossing the proximal interphalangeal and metacarpophalangeal joints of the middle finger (new input method). The switch turned on when the subject flexed his middle finger.

Results: The user successfully turned the switch on and typed almost the same numbers of characters per trial compared with the previous input method. The speed of his head movements during typing reduced (p?<?.01), and his sitting posture was nearly upright during computer operation (p?<?.01). No involuntary movement, requiring physical assistance, was observed when using the wearable switch.

Conclusion: The new switch system can be a new option for people with difficulty using standard handheld input devices due to paralysis and involuntary muscle movements.

• Implications for rehabilitation

• Cerebral palsy is a major cause of motor dysfunction and spasticity and dyskinesia in the fingers and upper limbs may prevent children with cerebral palsy from using handheld input devices.

• Wearable devices may be useful for children with cerebral palsy who have limited access to handheld pointing devices.

• We developed a new wearable switch to control devices using a flexible stretchable sensor.

• The wearable switch contributed to the improvement of sitting posture and reduction of neck burden during the typing task at the speed equivalent to that using the previous method in a child with mixed type of cerebral palsy exhibiting choreoathetotic movements and bilateral spasticity.

     

脑瘫患儿的碱性磷酸酶分析

目的探讨脑瘫患儿的碱性磷酸酶 (ALP)在不同型别脑瘫的差异及在分型诊断中的意义。方法对 40例不同类型的脑瘫患儿进行ALP测定。结果痉挛型脑瘫患儿的ALP值在正常范围内 ,手足徐动型脑瘫患儿的ALP值明显高于痉挛型脑瘫患儿的ALP值 (P <0 .0 0 1)。结论ALP值还可做为鉴别诊断的客观指标。     

Muscular dystonia and athetosis in six patients with congenital nephrotic syndrome of the Finnish type (NPHS1)

Congenital nephrotic syndrome of the Finnish type (NPHS1, CNF) is an autosomal recessively inherited disease occurring due to mutations in the nephrin gene (NPHS1). Two main Finnish mutations exist: Fin-major and minor, which both cause a lack of nephrin and absence of the slit diaphragm between the podocytes. This leads to severe proteinuria, nephrotic syndrome and infections, and without dialysis or renal transplantation, death in infancy. Between 1984 and 2003, six (8.6%) of the 70 NPHS1 patients diagnosed at our institution had, in addition to their renal disease, similar neurological symptoms. All six showed a severe dyskinetic cerebral palsy-like syndrome with dystonic features, athetosis and a hearing defect. The neurological symptoms became apparent during their 1st year of life and were diagnosed before 11 months of age. MRI showed increased signal intensity in T2-weighted images in the globus pallidus area. No mitochondrial gene mutations explaining the neurological symptoms were found, nor did external neurological complications explain them when compared with 29 NPHS1 control patients. Four children died at an early age: two during dialysis and two shortly after renal transplantation. Two are still alive with a functioning graft. Both have severe motor defects, but are mentally active and social.     

穴位埋线治疗小儿脑瘫临床观察

目的：观察穴位埋线治疗小儿脑瘫的临床疗效。方法：30例小儿脑瘫患者均采用基础治疗加穴位埋线治疗,治疗1个疗程后进行疗效比较。结果：痉挛型显效2例,有效7例,无效2例;手足徐动型显效1例,有效2例,无效1例;强直型显效1例,有效1例,无效1例;共济失调型显效1例,有效2例,无效2例;肌张力低下型显效3例,有效4例,无效0例。有效率为80%。结论：穴位埋线治疗后患儿症状明显改善,生活质量有所提高。     

Athetosis-dystonia in intramedullary lesions of spinal cord

Athetosis and dystonia are well known clinical signs, described in disorders of basal ganglia. As opposed to pseudoathetosis, true athetosis was hitherto not reported in cord lesions. We here report three patients with athetosis and dystonia of hands due to intramedullary lesions of cervical cord: two patients with syringomyelia and one with glioma. Even though pseudoathetosis can be produced by lesions of posterior columns and likely to be confused with the involuntary movements of our patients, they had clinical and EMG findings consistent with true athetosis. A possible explanation for the athetosis and dystonia due to cord lesion is being postulated.     

Improving Target Acquisition for Computer Users With Athetosis

Prior work has highlighted the challenges faced by people with athetosis when trying to acquire on-screen targets using a mouse or trackball. The difficulty of positioning the mouse cursor within a confined area has been identified as a challenging task. We have developed a target acquisition assistance algorithm that features transition assistance via directional gain variation based on target prediction, settling assistance via gain reduction in the vicinity of a predicted target, and expansion of the predicted target as the cursor approaches it. We evaluated the algorithm on improving target acquisition efficiency among seven participants with athetoid cerebral palsy. Our results showed that the algorithm significantly reduced the overall movement time by about 20%. Considering the target acquisition occurs countless times in the course of regular computer use, the accumulative effect of such improvements can be significant for improving the efficiency of computer interaction among people with athetosis.     

Posthemiplegic athetosis in the adult. CT findings in a case

In an adult patient with posthemiplegic athetosis the CT findings provide support for the theory that the physiopathogenetic substrate of the syndrome is damage to the strio-pallido-thalamocortical tract with relative sparing of the main corticospinal tract.

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Sommario Viene descritto un caso adulto di atetosi post-emiplegica, la cui topografia lesionale T.C. induce ad avvalorare la teoria del coinvolgimento della via strio-pallido-talamo-corticale, in presenza di relativa integrità della via cortico-spinale principale, quale sunstrato fisiopatogenetico della sindrome.

     

Magnetic Resonance Imaging in Athetotic Cerebral Palsied Children

ABSTRACT. The magnetic resonance findings in 22 children with athetotic cerebral palsy were studied. Sixteen had perinatal asphyxia, two had neonatal jaundice, and four had no association with predisposing conditions. In six of the children, symmetrical high intensity areas were found in both the thalamus and putamen in T2-weighted images. In five children they were seen only in the thalamus, and in another one only in the putamen. In six children, symmetrical periventricular high intensity areas were seen. In seven of the subjects, no abnormal magnetic resonance findings were seen. Magnetic resonance lesions, possibly caused by asphyxia, were found in the basal ganglia, thalamus and/or cerebral white matter in 14 of 16 children. Three children with lesions only in the cerebral white matter had mild motor abnormality, and six children with lesions in both the thalamus and putamen did not have mild abnormality.