Bob Baljet

The Innervation of the Spinal Dura mater: Anatomy and Clinical Implications

SummaryThe nerves supplying the spinal dura mater were studied in four human foetuses (16–22 weeks) with the acetylcholinesterasein toto staining method.The ventral spinal dura contains a dense, longitudinally oriented, nerve plexus, which receives its contributions from: (I) the sinuvertebral nerves, (II) the nerve plexus of the posterior longitudinal ligament, (III) the nerve plexus of radicular branches of segmental arteries.Dorsal dural nerves are much smaller in number, do not form an evident plexus and do not reach the medial region of the dorsal dura. The dorsal nerves are derived from the ventral dural plexus at the level of the “intersleeval” parts of the dura mater.The ventral dural nerves may extend up to eight segments, with a great amount of overlap between adjacent nerves. This may provide an anatomical substrate for the understanding of extrasegmentally referred dural pain. The curled bundles of nerve fibres of pathways (I) and (II) provide an adequate adaptation to displacements of the spinal dura mater during flexion and extension. Pathway (III) has not been described before. The described nerve plexuses may be of importance in elucidating the mechanisms of epidural therapies in back pain and peripheral vascular disease.

Pre- and post-ganglionic nerve fibres of the pterygopalatine ganglion and their allocation to the eyeball of rats

The origin, course and distribution of pre- and postganglionic neurons of the pterygopalatine ganglion (PPG) in the rat were studied using acetylcholinesterase staining, wheat germ agglutinin coupled to horseradish peroxidase (WGA-HRP) histochemistry and autoradiography. These methods were used in a selected and planned fashion to reveal details concerning the innervation of the lacrimal gland and portions of the eye. The PPG in rats consists of a rostral triangular portion and additional perikarya surrounding the distal part of the major petrosal nerve. Fibres from the superior cervical ganglion (SCG) reach the PPG via the inferior petrosal sinus. Application of WGA-HRP was made after transections: (1) rostral to the PPG; and (2) caudal to the PPG. The first of these applications labelled mainly fibres in the PPG; the second application labelled preganglionic parasympathetic brainstem neurons dorsolateral to the facial nucleus (i.e. the lacrimal nucleus), rostral cells in the SCG and trigeminal sensory fibres. WGA-HRP injections of the lacrimal gland, the conjunctiva and the anterior chamber of the eye all labelled cells in different parts of the PPG. This means that the PPG contains sensory and sympathetic nerve fibres and that the PPG has a topographical organisation along the rostrocaudal axis. Isotope injections of the PPG anterogradely labelled fibres passing through the ciliary ganglion that innervated the conjunctiva, the limbus and parts of the choroid.

Congenital anomalies in the teratological collection of museum Vrolik in Amsterdam, the Netherlands. II: skeletal dysplasias

The Museum Vrolik collection of the Department of Anatomy and Embryology of the University of Amsterdam, founded by Gerardus Vrolik (1775-1859) and his son Willem Vrolik (1801-1863), consists of more than five thousand specimens of human and animal anatomy, embryology, pathology, and congenital anomalies. Recently, the collection of congenital anomalies was recatalogued and redescribed according to contempory syndromological views. The original descriptions, as far as preserved, were compared with the clinical and radiographical findings. In 18 specimens the following skeletal dysplasias were diagnosed: achondrogenesis, achondroplasia, Blomstrand chondrodysplasia, Majewski syndrome, osteodysplastic primordial dwarfism, osteogenesis imperfecta type I, osteogenesis imperfecta type II, and thanatophoric dysplasia with and without cloverleaf skull. Radiography did not yield a diagnosis in 4 specimens. The use of additional diagnostical techniques, such as MRI and CT scanning and fluorescence in situ hybridization in these specimens, is currently being investigated.

Branches of the thoracic sympathetic trunk in the human fetus

SummaryThe segmental organization of the thoracic sympathetic trunk and all its ramifications was studied in 6 human fetuses (16–22 weeks) by means of the acetylcholinesterase in toto staining method. Each trunk was divided into 12 sympathetic segments. A segment is defined as that part of the sympathetic trunk which is connected via its rami communicates with one spinal nerve, without discriminating between grey and white rami. The diameter of the rami communicantes and their direction towards the spinal nerves are variable. The number of peripheral segmental ramifications of the trunk is much larger than assumed previously. Each thoracic sympathetic segment gives off at least 4–5 nerves. Three categories of nerves are discerned: (1) large splanchnic rootlets confined to the greater, lesser and least thoracic splanchnic nerves, (2) medium-sized splanchnic nerves directed towards thoracic viscera, some of which give off branches towards costovertebral joint plexuses and, described for the first time in man, (3) small nerves which ramify extensively and form nerve plexuses in the capsule of the costovertebral joints. The majority of the ramifications is formed by the nerves of the third category. The existence of Kuntzs nerve, connecting the 2nd intercostal nerve and 1st thoracic spinal nerve, is confirmed in four specimens. The nerve plexuses of the costovertebral joints receive a segmentally organized innervation: they receive their input from the neighbouring sympathetic segment and the one cranial to it.It is concluded that the thoracic sympathetic branches in man show a complex, segmentally organized pattern and may have a considerable component of somatosensory nerve fibers. The complex relationships must be taken into account in surgical sympathectomies.

Congenital anomalies in the teratological collection of museum Vrolik in Amsterdam, the Netherlands. I: syndromes with multiple congenital anomalies

The Museum Vrolik collection of the Department of Anatomy and Embryology of the University of Amsterdam, founded by Gerardus Vrolik (1775-1859) and his son Willem Vrolik (1801-1863), consists of more than 5,000 thousand specimens of human and animal anatomy, embryology, pathology, and congenital anomalies. Recently, the collection of congenital anomalies was recatalogued and redescribed according to contempory syndromological views. The original descriptions, as far as preserved, were compared with the clinical and radiographical findings. In 13 specimens the following multiple congenital anomalies (MCA) syndromes were diagnosed: acrofacial dysostosis, Apert syndrome, Brachmann-De Lange syndrome, ichthyosis congenita gravis, Jarcho-Levin syndrome, Meckel syndrome, oro-facio-digital syndrome type IV, Roberts syndrome, Smith-Lemli-Opitz syndrome, Treacher Collins syndrome, and trisomy 13. It appeared that the founders of the museum studied and described several of these syndromes many years before they became established as such. In some specimens a reliable diagnosis is still pending. The use of additional diagnostical techniques, such as MRI, CT scanning, and fluorescence in situ hybridization, in these specimens is currently being investigated.

A retrograde double fluorescent tracing study of the levator palpebrae superioris muscle in the cynomolgus monkey

In the cynomolgus monkey, motoneurons innervating the levator palpebrae superioris muscle form a nucleus within the oculomotor nuclei called the central caudal nucleus. After double fluorescent neuronal retrograde tracing experiments, using fast blue and diamidino yellow as tracers in the levator palpebrae superior muscles, labelled motoneurons (30%) were found in an unpaired central caudal nucleus. Approximately 2% of the labelled motoneurons were double-labelled. The labelled and double-labelled neurons were distributed randomly over the central caudal nucleus, lateralization of populations of levator motoneurons within this nucleus was not observed. The afferent innervation of the levator palpebrae superioris muscle was restricted to the ophthalmic branch area of the gasserian ganglion. Primary afferent labelled neurons were absent from mesencephalic nucleus of the fifth nerve. Surprisingly, fast blue was also found in the ophthalmic branch area of the contralateral ganglion of Gasser, while diamidino yellow was present only ipsilaterally. About 1% of the afferent labelled neurons were double-labelled. The results reveal that in the cynomolgus monkey the central caudal nucleus is not only topographically but also functionally one nucleus. Afferent innervation of the levator palpebrae superioris muscle is probably bilaterally organized.

Congenital anomalies in the teratological collection of museum Vrolik in Amsterdam, the Netherlands. v: conjoined and acardiac twins

The Museum Vrolik collection of the Department of Anatomy and Embryology of the Academic Medical Center, University of Amsterdam, founded by Gerardus Vrolik (1775-1859) and his son Willem Vrolik (1801-1863), consists of more than 5,000 specimens of human and animal anatomy, embryology, pathology, and congenital anomalies. Recently, the collection of congenital anomalies, comprising 360 specimens, was recatalogued and redescribed according to contemporary perspectives. The original descriptions, as far as preserved, were compared with the clinical, radiographic, and magnetic resonance imaging findings. We diagnosed 30 symmetrical conjoined twins (CTs), 11 parasitic CTs, and 16 acardiac twins. Within the group of symmetrical CTs, the following concomitant external anomalies were found in 15 specimens: neural tube defects, holoprosencephaly, cleft lip/palate, umbilical hernia, omphalocele, cloacal exstrophy, peromelia, polydactyly, and facial abnormalities suggestive of a chromosomal abnormality. We discuss the results in the light of historical and contemporary explanations regarding conjoined twinning, including the opinions of Gerardus and Willem Vrolik and of Louis Bolk, one of their successors.

Congenital anomalies in the teratological collection of Museum Vrolik in Amsterdam, The Netherlands. III : Primary field defects, sequences, and other complex anomalies

The Museum Vrolik collection of the Department of Anatomy and Embryology of the Academic Medical Center, University of Amsterdam, founded by Gerardus Vrolik (1775-1859) and his son Willem Vrolik (1801-1863), consists of more than 5,000 specimens of human and animal anatomy, embryology, pathology, and congenital anomalies. Recently, the collection of congenital anomalies, comprising 360 specimens, was recatalogued and redescribed according to contemporary morphogenetic views. The original descriptions, if preserved, were compared with the clinical, radiographical, and magnetic resonance imaging findings. In 120 specimens the following midline anomalies, primary field defects, and sequences were diagnosed: holoprosencephaly sequence; aprosencephaly/atelencephaly; cleft lip; Pierre Robin sequence; omphalocele; diaphragmatic hernia; ectopic heart; bladder exstrophy; cloacal exstrophy; caudal dysgenesis; prune belly sequence; sirenomelia; fetal akinesia sequence; and disruption sequences. Polytopic field defects and associations were diagnosed in 25 specimens. We discuss the opinions of Gerardus and Willem Vrolik, who tried to find reasonable explanations for the dysmorphogenetic entities they investigated, rather than accepting the traditional superstitions.

Congenital anomalies in the teratological collection of museum Vrolik in Amsterdam, the Netherlands. iv: closure defects of the neural tube

The Museum Vrolik collection of the Department of Anatomy and Embryology of the University of Amsterdam, founded by Gerardus Vrolik (1775-1859) and his son Willem Vrolik (1801-1863), consists of more than 5,000 specimens of human and animal anatomy, embryology, pathology, and congenital anomalies. Recently, the collection of congenital anomalies, comprising 360 specimens, was recatalogued and redescribed according to contemporary morphogenetic opinions. The original descriptions, as far as preserved, were compared with the clinical and additional findings. Based on the classification by closure site, proposed by Van Allen et al. [1993], the following closure defects of the neural tube were diagnosed in 107 specimens: craniorachischisis, holoacranium with partial rachischisis, faciocranioschisis, holoacranium, meroacranium, occipital cranioschisis, frontal encephalocele, parietal encephalocele, occipital encephalocele, occipital encephalocele with rachischisis, occipito-cervical encephalocele, thoracolumbar spina bifida, lumbosacral spina bifida, occult sacral dysraphism, and sacrococcygeal dysgenesis. Furthermore, we diagnosed three conditions that did not appear in the aforementioned classification; we named these conditions craniorachischisis totalis, occipital craniorachischisis, and thoracolumbosacral spina bifida. The results of our study are in line with the assumption that particularly occipito-cervical neural tube defects are associated with concomitant anomalies and are more common in females. The results support the idea of multisite closure of the human neural tube.

Calcitonin gene-related peptide and substance P immunoreactivity in the monkey trigeminal ganglion, an electron microscopic study.

Calcitonin gene-related peptide (CGRP) and substance P (SP) immunoreactivity was examined in neurons of the monkey trigeminal ganglion. Moreover, CGRP- and SP-positive varicose nerve fibers were found, occasionally forming pericellular arborizations around trigeminal somata, which, at light microscopic level, suggested the existence of synaptic contacts. Electron microscopic investigation however, revealed that although these varicose fibers ran in close range of somata and were containing accumulations of CGRP- and SP-positive vesicles, classical synaptic contacts were not present.