Clinical course of porokeratosis ptychotropica over 7 years in an otherwise healthy child

Porokeratosis ptychotropica is an unusual variant of porokeratosis characterized by papules and plaques located on the buttocks and gluteal cleft and showing multiple coronoid lamellae on histology. In this case report, we present the longitudinal clinical course of porokeratosis ptychotropica in a pediatric patient with individual red-brown hyperkeratotic lesions that enlarged and became confluent prior to surgical intervention. We also discuss the etiology of porokeratosis ptychotropica and review current as well as future treatment options for the disease.     

Differentiation of ulnar neuropathy at the wrist due to ganglion cyst from ulnar neuropathy at the elbow

ObjectiveHere, we aimed to describe the clinical, electrodiagnostic (EDx) and ultrasonographic (US) findings in a series of patients with ulnar neuropathy at the wrist (UNW) due to compression by a ganglion cyst. We also sought features that differentiate UNW from ulnar neuropathy at the elbow (UNE).MethodsWe reviewed electronic medical records of consecutive patients with UNW caused by ganglion cysts. We compared their clinical, EDx and US findings to findings in our previously reported prospective series of UNE patients.ResultsWe identified 10 patients with UNW caused by ganglion cyst compression, who all presented with intrinsic hand muscle weakness and atrophy. Compared to 175 UNE patients they less often complained of paresthesia (60% vs. 98%) and presented less sensory loss in the palm (30% vs. 96%) and little finger (50% vs. 95%). They more often had distal ulnar motor latency recorded from the abductor digiti minimi (ADM) > 3.6 ms (80% vs. 30%), and denervation activity on needle EMG in the first dorsal interosseous (FDI) compared to ADM (100% vs. 60%). Only 20% of our UNW patients had ulnar nerve swelling at the site of compression on US.ConclusionUNW potentially caused by ganglion cyst should be suspected in patients presenting with intrinsic hand muscle atrophy and weakness, particularly in cases with normal sensation, increased distal ulnar motor latency recorded from ADM and more severe neuropathic changes in FDI compared to ADM muscle.     

The Sensational Hand: Clinical Assessment after Nerve Repair

Following the transection and repair of major nerve trunks in the forearm, the functional outcome is influenced by mechanisms in the peripheral, as well as in the central nervous system. In the present thesis the interest is focused on assessment of the outcome after nerve repair, central nervous factors influencing the outcome, and sense substitution to compensate for sensory loss. A new model instrument for routine documentation of the outcome after repair of a peripheral nerve is identified. The model includes assessments reflecting sensory, motor and pain/discomfort domains. Investigations of frequently used assessment instruments led to the construction and evaluation of a new test instrument for assessment of discriminative sensibility (tactile gnosis) to fit in the model. The summarised outcome, calculated from the model instrument and with a numerical scoring system, conforms well with the patient's opinion on the influence on activities of daily living resulting from the nerve injury, and demonstrates good reliability and validity. A reference interval for the outcome is presented, with the estimated 95% predicted values for the outcome up to five years after the nerve repair. Brain plasticity is a factor sensibility - tactile gnosis - in the adaptive process after a nerve injury, when the mind has to interpret new signal patterns, when objects are touched. For better understanding of the sensory outcome after nerve repair, central nervous factors were examined. Specific cognitive capacities, such as verbal learning and visuo-spatial logic capacity could be identified as being of importance for recovery of tactile gnosis. For patients with temporary or permanent sensory loss, a new principle for artificial sensibility based on sense substitution is presented. The hearing sense substitutes the sense of touch. The resemblance in perceptual experience between sound and touch is bridged by the stereophonic friction sound generated by touching objects, which is then amplified and transmitted to earphones. The delicate capacity of the sense of hearing to discriminate between the complex pattern of frequencies makes it reasonable to assume that hearing is able to take over functions normally devoted to touch. This is demonstrated in the thesis.     

Investigation of Ultrasound-Measured Flow Velocity,Flow Rate and Wall Shear Rate in Radial and Ulnar Arteries Using Simulation

Parameters of blood flow measured by ultrasound in radial and ulnar arteries, such as flow velocity, flow rate and wall shear rate, are widely used in clinical practice and clinical research. Investigation of these measurements is useful for evaluating accuracy and providing knowledge of error sources. A method for simulating the spectral Doppler ultrasound measurement process was developed with computational fluid dynamics providing flow-field data. Specific scanning factors were adjusted to investigate their influence on estimation of the maximum velocity waveform, and flow rate and wall shear rate were derived using the Womersley equation. The overestimation in maximum velocity increases greatly (peak systolic from about 10% to 30%, time-averaged from about 30% to 50%) when the beam–vessel angle is changed from 30° to 70°. The Womersley equation was able to estimate flow rate in both arteries with less than 3% error, but performed better in the radial artery (2.3% overestimation) than the ulnar artery (15.4% underestimation) in estimating wall shear rate. It is concluded that measurements of flow parameters in the radial and ulnar arteries with clinical ultrasound scanners are prone to clinically significant errors.