Richard J. Konkol

Möbius syndrome: evidence for a vascular etiology.

We report five infants with restricted lateral gaze, facial diplegia, feeding difficulty, and/or respiratory disorders without significant pulmonary disease. Viral studies were negative in all patients. Two children had radiologic findings that included brain-stem hypoplasia and symmetric calcification in the dorsal tectum at the junction of the midbrain and pons. Autopsy of one of these two children demonstrated capillary telangiectasia in the mesencephalon and pons. The other three children had normal computed tomographic (CT) scans. However, their autopsies revealed focal brain-stem necrosis with calcifications but without vascular malformation. We suggest that the capillary malformations in one of our patients directly resulted in a vascular-induced necrosis and the manifestation of Möbius sequence. The similarity of symmetric neuropathologic findings in the three other patients and the CT scan in the one surviving patient suggest focal hemodynamic changes restricted to the posterior circulation, indirectly supporting a vascular theory of embryopathogenesis. (J Child Neurol 1993;8:260-265).

Infantile spasms in children with Down syndrome

The authors retrospectively identified 17 children with Down syndrome who developed infantile spasms, and analysed their etiology, EEG findings, response to medication, development and prognosis. Compared with symptomatic infantile spasms in the general population, which have a poor prognosis, these patients had a relatively benign outcome with regard to seizure control: only three of 16 survivors currently have seizures and seven of the 16 currently receive anticonvulsants. Developmental outcome was poorest in those with a superimposed hypoxic insult and in those who regressed developmentally at the onset of the spasms and did not regain developmental milestones. The overall neurological prognosis for children with Down syndrome and infantile spasms appears to be better than for children with infantile spasms in the general population.

Cocaine and benzoylecgonine constrict cerebral arteries by different mechanisms.

This study was designed to determine possible mechanisms underlying the vasoconstrictor activity of cocaine and its principal metabolite, benzoylecgonine (BE) in cat isolated cerebral arteries. The arteries constricted significantly in response to single doses of cocaine, BE and norepinephrine (NE; (P < 0.05). After 6-OHDA treatment to remove adrenergic nerve endings, NE-induced constrictions were essentially unchanged from those before treatment. Denervated arteries exposed to cocaine dilated significantly (P < 0.05) but those exposed to BE constricted as much as before denervation. Following exposure to prazosin and yohimbine, arterial constrictions to NE and cocaine were significantly reduced from control (P < 0.05) but the BE-induced constriction was unchanged. Ryanodine eliminated the cocaine-induced contraction (P < 0.05) whereas verapamil eliminated the BE response (P < 0.05). These data suggest that while cocaines vasoconstrictor action may be significantly mediated through adrenergic transmission, BE may act through a mechanism involving calcium (Ca2+) channels. Cocaine levels peak and decline in the body more rapidly than BE levels which can remain detectable for days. This study suggests there may also be different pharmacological mechanisms as well as temporal differences underlying the vasoreactivity of these two substances. Our findings may have implications for pharmacological management of cocaine-induced toxic vascular events.

Familial Hemiplegic Migraine With Crossed Cerebellar Diaschisis and Unilateral Meningeal Enhancement

A 6‐year‐old boy with a family history of hemiplegic migraine had a hemiplegic migraine lasting for 6 days complicated by prolonged fever, lethargy, and two brief focal seizures. An acute single photon emission computerized tomogram (SPECT) demonstrated decreased blood flow in the symptomatic cerebral hemisphere as well as crossed cerebellar diaschisis not previously documented in migraine. Another unique finding was the MRI with enhancement of the meninges and pial vessels over the symptomatic cerebral hemisphere. These findings suggest cerebellar and extra‐axial involvement as components of hemiplegic migraine.

Quantitation of benzoylnorecgonine and other cocaine metabolites in meconium by high-performance liquid chromatography

A method for simultaneous extraction of cocaine and metabolites benzoylnorecgonine, benzoylecgonine and norcocaine from meconium was developed. The procedure uses solid-phase extraction columns with both cation-exchange and hydrophobic properties after vortex-mixing meconium with methanol. Chromatography utilizes reversed-phase high-performance liquid chromatography with a C18 column and phosphate buffer-acetonitrile as mobile phase. The method is specific and sensitive to 50 ng/g meconium for all compounds. Standard curves are linear from 0.05 to 5.0 micrograms/g (r2 > or = 0.989). Intra-assay coefficients of variation were < or = 6.9%. Meconium from infants exposed to cocaine in utero contained varying combinations of the four drugs.

Mobius syndrome: Electrophysiologic studies in seven cases

Mobius syndrome is characterized by congenital facial diplegia, frequent impairment of gaze, variable involvement of other cranial muscles, and various musculoskeletal anomalies. The site of dysfunction remains debatable. We performed detailed electrophysiologic studies in 5 children and 2 adults with Mobius syndrome to better delineate the pathophysiology of this disorder. Sensory and motor conduction studies were normal in the extremities. Facial compound muscle action potential amplitudes were reduced in all patients. The blink reflex R1 responses were unobtainable unilaterally in 2 patients and unobtainable bilaterally in 3 patients. Otherwise, R1 and R2 latencies were variably prolonged. The jaw jerk and masseter silent periods, tested in 2 patients, were normal. Detailed electromyographic studies of facial muscles revealed multifocal, chronic neurogenic changes. The findings indicate a brain stem process predominantly affecting the facial nuclei and their internuclear connections, rather than a supranuclear or muscular site of involvement.

Effect of cocaine metabolites on behavior: Possible neuroendocrine mechanisms

The predominant cocaine metabolites were tested for central nervous system effects by intracerebroventricular (ICV) administration in rats. We found two types of responses: cocaine, norcocaine (NC), benzoylecgonine (BE), and benzoylnorecgonine (Nor BE) produced stimulatory effects, whereas ecgonine methyl ester (EME) and ecgonine (EC) resulted in no specific effect or sedation. A novel metabolite interaction was revealed when rats were pretreated with EME, which inhibited both analgesia and seizures by subsequently administered cocaine. Pretreatment with EC inhibited both cocaine and BE seizures and seizure-associated death. Direct injection of EME into the nucleus accumbens significantly suppressed systemic cocaine potentiation of intracranial electrical self-stimulation of the ventral tegmental area, whereas corticotropin releasing hormone injected ICV selectively potentiated BE-induced seizures and death. These results confirm multiple, metabolite-mediated activities in the central nervous system. Pharmacological interactions of the metabolites with each other and/or with neurohormones may help explain some of the pathophysiological effects seen in human chronic cocaine abuse.The predominant cocaine metabolites were tested for central nervous system effects by intracerebroventricular (ICV) administration in rats. We found two types of responses: cocaine, norcocaine (NC), benzoylecgonine (BE), and benzoylnorecgonine (Nor BE) produced stimulatory effects, whereas ecgonine methyl ester (EME) and ecgonine (EC) resulted in no specific effect or sedation. A novel metabolite interaction was revealed when rats were pretreated with EME, which inhibited both analgesia and seizures by subsequently administered cocaine. Pretreatment with EC inhibited both cocaine and BE seizures and seizure-associated death. Direct injection of EME into the nucleus accumbens significantly suppressed systemic cocaine potentiation of intracranial electrical self-stimulation of the ventral tegmental area, whereas corticotropin releasing hormone injected ICV selectively potentiated BE-induced seizures and death. These results confirm multiple, metabolite-mediated activities in the central nervous system. Pharmacological interactions of the metabolites with each other and/or with neurohormones may help explain some of the pathophysiological effects seen in human chronic cocaine abuse.

Is There a Cocaine Baby Syndrome

Received March 9, 1994. Received revised March 21, 1994. Accepted for publication March 24, 1994. From the Division of Pediatric Neurology, Oregon Health Sciences University, Portland, OR. Address correspondence to Dr R.J. Konkol, Division of Pediatric Neurology, Oregon Health Sciences University, 745 SW Gaines Road, CDW-1, Portland, OR 97210. Over the last few decades, young adults and teenagers of child-bearing age have been exposed to a variety of drugs with potentially adverse effects on the outcome of pregnancy. In the United States, over 50% of fetuses are

In vivo pharmacokinetics and in vitro production of cocaethylene in pregnant guinea pigs

Simultaneous exposure to cocaine and ethanol results in the formation of cocaethylene, an active metabolite of cocaine. The concurrent abuse of both cocaine and ethanol is common during human pregnancy, but the kinetics of elimination and formation of this ethyl ester of cocaine have not been studied during pregnancy in any species. In the late gestation guinea pig (61 to 63 days), cocaethylene, at doses of 2 to 4 mg.kg-1, is rapidly eliminated with a half-life of 29 min and a total body clearance of 77 ml.min-1.kg-1. It is formed enzymatically by hepatic microsomal preparations from fetal, neonatal and maternal guinea pigs. The maximum rate of cocaethylene production (apparent Vmax) when either ethanol or cocaine are varied while the other substrate is held constant, increases with age, from the late fetal period (65 days gestation, term 70 days) to adulthood. However, the Michaelis-Menten constant (apparent KM) does not change with age. The rapid elimination of cocaethylene, coupled with the slow rate of formation (apparent Vmax of 140 pmol.min-1.mg microsomal protein-1) and the small amount of plasma analyzed most likely explains the inability to detect coacethylene in vivo after concomitant cocaine and ethanol administration.

Migraine-associated vomiting and asystole in a child.

A variety of symptoms that accompany migraine in the child and adult are mediated by the autonomic nervous system. Significant effects on cardiac rhythm are uncommon, but can be life threatening. We describe a 3‐year‐old girl in whom migraine‐associated vomiting precipitated cardiac asystole which was effectively treated with a cardiac pacemaker.