Cranial

A rapidly growing use in the medical field is for surgical implants as either bone plates and screws, joint replacements, or for the repair of cranial injuries. Here, titanium and its alloys have the advantages of complete compatibility with body fluids, low density, and low modulus. Applications also exist in dentistry. 

These are a subset of sensory neurons having their cell bodies (small to medium size) in dorsal root and in cranial nerve ganglia and possessing nonmyelinated (C-type) or thinly myelinated (A-delta type) fibres. This subset of neurons express transient receptor potential vanilloid type 1 (TRPV1, or vanilloid, or capsaicin receptor) that is excited by capsaicin, the pungent ingredient of chilli. These neurons have been classified as polymodal nociceptors because they can be excited by various noxious stimuli. 

The pituitary gland lies deep within the cranial vault, connected to the brain by the infundibular stalk (a downward extension of the floor of the third ventricle) and protected by an indentation of the sphenoid bone called the sella turcica (see Fig. 50-1). The pituitary gland, a small, gray rounded structure, has two parts ... 

The 8 C values of the Preclassic humans at Cuello (Table 2.1) average -12.9 0.9%o (n = 28) in collagen, -9.8 1.0 in bone apatite (n = 16), and -8.7 2.3%o in tooth enamel apatite (n = 33) the S N values in collagen average 8.9 1.0%o (n = 23). The discrepancy in the number of specimens is due to the fact that more teeth were available than post-cranial material, while some of the specimens contained insufficient collagen to measure the nitrogen isotope ratios. Additional bone apatite analyses are in progress. 

The clinical presentation of MM in HIV-infected patients is similar to that in other patients with vasculitic neuropathy (Hoke and Comblath 2004). It is characterized by symptoms and signs of sensory involvement, with numbness and tingling in the distribution of one peripheral nerve trunk. Sequential involvement of other noncontiguous peripheral or cranial nerves progresses over days to weeks. The initial multifocal and random neurologic features may evolve to symmetrical neuropathy (Ferrari et al. 2006). 

DIES-associated neuropathy has a variety of chnical presentations, including painful symmetric or asymmetric sensorimotor neuropathy, distal sensory neuropathy, mononeuritis multiplex, and demyelinating polyneuropathy (Gherardi et al. 1998). Cranial neuropathy without evidence of a more generahzed neuropathy may occur, typically as a facial nerve palsy in association with parotidomegaly (Itescu et al. 1990 Brew 2003). The neuropathy develops subacutely over days to weeks. In some cases, muscle weakness may be a result of an inflammatory myositis (Kazi et al. 1996). 

Tetanus occurs when Cl. tetani, ubiquitous in the soil and faeces, contaminates wounds, especially deep puncture-type lesions. These might be minor traumas such as a splinter, or major ones such as battle injury. At these sites, tissue necrosis and possibly microbial growth reduce the oxygen tension to allow this anaerobe to multiply. Its growth is accompanied by the production of a highly potent toxin which passes up peripheral nerves and diSuses locally within the central nervous system. It acts like strychnine by affecting normal function at the synapses. Since the motor nerves of the brain stem are the shortest, the cranial nerves are the first affected, with twitches of the eyes and spasms of the jaw (lockjaw). 

Schriger DL, Kalafut M, Starkman S, Krueger M, Saver JL. Cranial computed tomography interpretation in acute stroke physician accuracy in determining eligibility for thrombolytic therapy. JAMA. 1998 279 1293-1297. 

Decompressive Expansion of cranial Wide craniectomy with ICP monitoring recommended Death, ICH,... 

Acute exposure to trichloroethylene and its decomposition products (e.g., dichloroacetylene) has also led to residual neuropathy, characterized by nerve damage. This neuropathy is characterized by facial numbness, jaw weakness, and facial discomfort (indicating damage to cranial nerves V and VII) which can persist for several months (Buxton and Hayward 1967 Feldman 1970). Chronic exposure in the workplace has also been associated with damage to the cranial nerves in several cases (Bardodej and Vyskocil 1956 Barret et al. 1987 Cavanagh and Buxton 1989). Persons who have died from overexposure have shown degeneration of cranial nuclei in the brain stem (Buxton and Hayward 1967). Some of these effects may be attributed to... 

It is not clear if the effects on cranial nerve dysfunction from inhalation exposure are attributable to trichloroethylene or its decomposition products. For example, while a number of limited animal studies report neuropathies associated with exposure to trichloroethylene (Bardodej and Vyskocil 1956 Barret et al. 1987 Lawrence and Partyka 1981 McCunney 1988), there are some animal studies which report that these effects resulted from exposure to the trichloroethylene decomposition product, dichloroacetylene (Barret et al. 1992 Buxton and Hayward 1967 Cavanagh and Buxton 1989 Feldman 1970 Humphrey and McClelland 1944). 

Buxton PH, Hayward M. 1967. Polyneuritis cranials associated with industrial trichloroethylene poisoning. J Neurol Neurosurg Psychiatry 30 511-518. 

Cavanagh JB, Buxton PH. 1989. Trichloroethylene cranial neuropathy Is it really a toxic neuropathy or does it activate latent herpes virus J Neurol Neurosurg Psychiatry 52 297-303. 

Humphrey JH, McClelland M. 1944. Cranial-nerve palsies with herpes following general anaesthesia. Br MedJ 1 315-318. 

The so-called inferior group (B1-B4) projects mainly to brainstem nuclei, the head nuclei of some cranial nerves and the spinal cord. This means that these neurons are well placed for serving a key role in regulation of motor activity, autonomic function and nociception. In addition, there are numerous interconnections between the different... 

Figure 21.1 Some of the mediators of pain at the peripheral level with their receptors. Note that with regard to 5-HT, the cranial mechanisms have been omitted for clarity...

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