Cerebral abscess

Signs and Symptoms Depend on the site of infection. Infection may produce osteomyelitis or arthritis pneumonia [with chills, productive cough, low blood pressure (hypotension), difficulty breathing (dyspnea), or chest pain] meningitis or cerebral abscesses (with headache, fever, vomiting, stupor, coma) or intra-abdominal infections (with biliary drainage, hepatic abscess, pancreatic abscess, peritoneal exudate). 

Misdiagnosis of stroke is not uncommon and it is well recognized that nonvascular conditions such as brain tumor, subdural hematoma and cerebral abscess may mimic cerebral ischemia (Groch et al. 1960). Misdiagnosis occurs if details regarding past history are lacking. This may be because the patient is aphasic, comatose or demented. A careful patient... 

Although intracranial mass lesions such as cerebral abscess, subdural hematoma and brain tumors do not usually present with acute stroke-like symptom onset, 6% of brain tumor patients presented with symptoms of less than 24-h duration (Snyder et al. 1993). Misdiagnosis of these cases is easily prevented by CT or MRI and should not play a major role nowadays. 

Holmes TM, Petrella JR, Pi oveiizale JM (2004) Drsdnedon between cerebral abscesses and lirgli-gi ade neoplasms by dynamic suscepdbil-ity contrast perfusion MRI. AJR Am J Roentgenol 183 1247—1252. 

Poskitt KJ, Steinbok P, Flodmark O. Methotrexate leuko-encephalopathy mimicking cerebral abscess on CT brain scan. Childs Nerv Syst 1988 4(2) 119-21. 

Because catastrophic cerebral events such as cerebral abscess, transient ischemic attack or embolic stroke occur in patients with PAVMs regardless of the degree of respiratory symptoms, it is of paramount importance to diagnose PAVMs to offer embolization as a means of prevention. 

Long-term follow-up of patients treated with embolization has been reported in several studies [11,40, 55, 60, 71, 77]. In a recent study, the long-term outcomes of embolization (mean follow-up 62 months), were successful in 83% of 112 treated patients overall and in 96% of patients in whom all angiographi-cally visible PAVMs were embolized [40]. During the follow-up after embolization major neurological complications such as cerebral abscess, transient ischemic attack, or stroke related to reperfused treated or new PAVMs have been reported [11,25,40, 77]. The long-term morbidity of reperfused PAVMs is unknown but some patients have already suffered from stroke because of recanalized PAVMs [40]. 

Toxoplasmosis produces poorly specific symptoms or neurological signs (encephalitis, cerebral abscess), pneumopathy and/or chorioretinitis. 

Telangiectasias are collections of dilated capillaries that are usually of no clinical significance (Milandre et al. 1987). They may be associated with hereditary hemorrhagic telangiectasia (the Osler-Weber-Rendu syndrome), but this is more likely to be associated with neurological complications from a pulmonary arteriovenous malformation with right-to-left shunting, such as cerebral hypoxia, brain abscess, paradoxical and septic embolism, or from an associated intracranial arteriovenous malformation or aneurysm (McDonald et al. 1998). 

One girl in her third year, who had been immunized against tuberculosis at birth, developed an abscess of the associated lymph nodes (which were extirpated) and some weeks later developed intestinal BCG dissemination, which appeared to be cured by tuberculostatic treatment. Despite this, at the age of 22 years she developed a leftsided hemiplegia due to aneurysms and thrombosis of cerebral arteries, and 4 years later an oculomotor nerve paralysis was diagnosed. She died at 26 from recurrent intestinal BCG dissemination, which developed at the end of a pregnancy (a healthy premature child was bom). 

Brain abscess formation was studied experimentally in rats, and treatment with different combinations of hyaluronidase, dexamethasone, and antibiotic has been investigated [128]. The results showed that combined therapy with antibiotic and hyaluronidase, started the day before inoculation, averted the formation of brain abscess and the therapy, started after encapsulation, effectively eliminated the organisms. However, the same therapy started at the cerebritis stages caused an increase of cerebritis. 

Cerebritis is focal inflammation of brain parenchyma myelitis in the spinal cord). Cerebritis precedes abscess formation but requires an early biopsy to be seen (see Tables 20.2 and 20.10). The inflammatory infiltrate is composed of neutrophils, macrophages, lymphocytes, and plasma cells, with or without parenchymal necrosis. Septic cerebritis is usually caused by bacterial agents, most often streptococci or staphylococci, and less commonly by gram-negative organisms, such as Escherichia coli. Pseudomonas, and Haemophilus influenzae. Cerebritis also occurs around neoplasms, ruptured vascular malformations, infarcts, and traumatic lesions. 

One application of this technique is in making a brain scan. When "Tc04 is injected into a normal patient, it is prevented from entering the brain by a physiological blood brain barrier." However, abnormalities such as tumors and abscesses destroy this barrier, and there is an accumulation of activity in the cerebral tissue. The technique can also be used in the detection of abnormalities in the ureters, kidneys, and bladder, of bone cancer, and of a variety of other pathological conditions. 

Distribution Clindamycin is widely distributed in many fluids and tissues, including bone. Significant concentrations are not attained in CSF, but concentrations sufficient to treat cerebral toxoplasmosis are achieved. The drug readily crosses the placenta. Ninety percent or more of clindamycin is bound to plasma proteins. Clindamycin accumulates in polymorphonuclear leukocytes and alveolar macrophages and in abscesses. 

PAVMs provide a direct capillary-free communication between the pulmonary and systemic circulations with three main clinical consequences (1) pulmonary arterialbloodpassing through these right-to-left shunts cannot be oxygenated which may lead to hypoxemia, (2) the absence of normal filtering capillary bed allows particulate material (air bubbles or clots) to reach directly the systemic circulation (paradoxical embolism) with potential clinical sequelae in the cerebral circulation (transient ischemic attack, stroke, brain abscess), and (3) these abnormal vessels may rupture into the bronchus (hemoptysis) or the pleural cavity (hemothorax) particularly during pregnancy. 

Chagla AS, Balasubramaniam S. Cerebral N-butyl cyanoacrylate glue-induced abscess complicating embolization. J Neurosurg 2008 109(2) 347. 

---