Memory systems involved in professional skills: a case of dense amnesia due to herpes simplex viral encephalitis

JL, a 25-year-old physiotherapist, became densely amnesic following herpes simplex viral encephalitis (HSVE), causing bilateral damage to medial and ventral areas of her frontal and temporal lobes and their associated circuitry. Three years post-onset, her WAIS-R full scale IQ (Verbal 74, Performance 102) showed an estimated loss of +/- 50 points. She displayed severe global amnesia and markedly impaired social cognition. However, her immediate memory, perceptual priming, and cognitive problem-solving abilities were relatively spared. Her retention of professional skills was assessed using simulated physiotherapy scenarios. JL was able to demonstrate some procedural skills spontaneously, but was unable to apply them precisely and flexibly to individual patient needs. She showed no memory of theoretical or propositional physiotherapy knowledge, and could neither plan treatment nor reason clinically. Her performance was well below that of four other physiotherapists who had also not practised for 4 years. Thus, despite the relative sparing of her implicit memory, JL's performance lacked the co-ordinated operation of declarative and implicit long-term memory and the links to working memory that are necessary for the flexible performance of complex professional procedures.     

Training functional skills following herpes simplex encephalitis: A single case study

Abstract

This paper presents a treatment program for the development of personal hygiene behavior in a patient who was 5 years post herpes simplex encephalitis. The patient has severe memory and organizational problems, but is of average overall intelligence. The program consists in part of chaining a series of nine discrete activities by using linking phrases. The program allowed the patient to structure his behavior and wash in a well-organized nonrepetitive way. Results are discussed in the light of previous failures to affect behavior using apparently similar methods.     

Training functional skills following herpes simplex encephalitis: a single case study

This paper presents a treatment program for the development of personal hygiene behavior in a patient who was 5 years post herpes simplex encephalitis. The patient has severe memory and organizational problems, but is of average overall intelligence. The program consists in part of chaining a series of nine discrete activities by using linking phrases. The program allowed the patient to structure his behavior and wash in a well-organized nonrepetitive way. Results are discussed in the light of previous failures to affect behavior using apparently similar methods.     

Disproportionate retrograde amnesia in a patient with herpes simplex encephalitis

We describe a patient who developed a severe but temporally limited retrograde amnesia coupled with a relatively mild anterograde amnesia following herpes simplex encephalitis. The patient showed a profound retrograde amnesia for autobiographical events extending for about 10 years prior to the disease onset. Her knowledge about public events and famous persons was also impaired for this period. An MRI and SPECT demonstrated bilateral medial temporal pathology. This case represents a further instance of a relatively focal retrograde amnesia following brain damage. We review other reported cases with focal retrograde amnesia and consider theoretical and neuroanatomical accounts for the present case. Two factors may account for her amnesic patterns: a partial disruption of the store for premorbid binding codes (i.e., information that multimodal feature representations occurred synchronously); along with a relative preservation of the encoding process required to develop new synchronous codes.     

Chronic encephalitis possibly due to herpes simplex virus: two cases

Two patients had clinical findings of encephalopathy that progressed in 4 to 5 months. One patient had headache, fatigue, lethargy, hemiparesis, and a seizure. The second patient had only forgetfulness, confusion, and lethargy without focal signs. Herpes simplex virus was grown from brain biopsy in the first patient and from CSF in the second patient. These cases suggest that herpes simplex virus caused the encephalitis and that it should be considered in the differential diagnosis of chronic encephalopathy.     

A mild form of brain stem encephalitis due to herpes simplex virus

A 10-year-old boy had gait and speech disturbances 17 days after the initial symptoms of a fever, headache and cough. Four days later he was admitted to a hospital with mild disturbances of gait, speech, writing, visual acuity, left facial nerve, nystagmus and consciousness. Impairments of cranial nerves (II, III and VII), pyramidal sign and cerebellar sign were noticed. EEG showed generalized slow waves. Auditory brain stem response showed prolongation of the interval between I and V waves and poor differentiation between them. Brain CT could not find any abnormalities. Brain stem encephalitis was diagnosed. Clinical signs and symptoms continued for two weeks when steroid therapy was started and it was effective to improve the disease. He was discharged from the hospital without sequelae. Herpes simplex virus (HSV) type 1 was detected from cells in CSF on admission by fluorescence antibody method. HSV antibody titers in sera changed from 1/8 to 1/64 during three months by complement fixation test. Specific IgG and IgA by enzyme linked immunosorbent assay (ELISA) was high in CSF. Specific antibody in CSF/total antibody in CSF: specific antibody in serum/total antibody in serum for IgG and IgA classes were more than 1. Reports of mild type of HSV brain stem encephalitis seemed to be rare. Our case which was followed for several months carefully would be important to discuss.     

Relapsing herpes simplex encephalitis: pathological confirmation of viral reactivation

This case is reported to raise awareness of herpes simplex encephalitis as a persisting brain disorder. A 66 year old immunocompetent man developed status epilepticus and died of pneumonia in the course of progressive hemiparesis, cognitive decline, and atrophy of the brain over a five year period after herpes simplex encephalitis. In addition to a completely destroyed left temporal lobe, necropsy revealed active encephalitis consisting of necrosis and lymphocyte infiltration with a large number of intranuclear inclusions in the neurones and glial cells in the markedly oedematous parenchyma of the right frontal and parietal lobes. Herpes simplex virus type 1 (HSV-1) antigen was detected by immunohistochemistry, HSV-1 DNA by in situ hybridisation, and herpes simplex virus nucleocapsids by electronmicroscopy. These clinical and pathological findings suggest that direct viral reactivation might result in a relapse of herpes simplex encephalitis, causing progressive clinical deterioration associated with the persistence of HSV-1 in the brain. This is the first case report demonstrating HSV-1 antigen, HSV-1 DNA, and herpes simplex virus nucleocapsids in a case of relapsing herpes simplex encephalitis.     

Virus reactivation after immunotherapy of anti-NMDAR encephalitis secondary to herpes simplex encephalitis: A case report

Herpes simplex encephalitis is the most common cause of sporadic fatal encephalitis. More than half of patients with herpes simplex encephalitis will die and the vast majority of survivors have severe neurologic sequelae without effective antiviral therapy. Some people experience relapses such as secondary anti-N-methyl-d-aspartate receptor encephalitis despite appropriate antiviral treatment. It is rare that virus reactivation after immunotherapy of anti-N-methyl-d-aspartate receptor encephalitis after herpes simplex encephalitis. In the present study, we retrospectively review one patient who showed this rare situation.     

A high aged case of herpes simplex viral encephalitis associated with progressive cerebral white matter lesion]

An 80-year-old male without abnormal past medical history presented with coma, general seizures, and fever subsequent to abnormal behavior. The pressure of the cerebrospinal fluid(CSF) elevated(13.5-20.5 cm H2O), and CSF examination revealed pleocytosis with predominant mononuclear cells(80-879/mm3) and elevated protein level(32-130 mg/dl). DNAs of herpes simplex virus(HSV) type 1 and 2 in CSF were not confirmed by polymerase chain reaction method in the acute phase. The HSV(type 1) antibody(HSV-1 Ab) ratio of serum to CSF(= [serum HSV-1 Ab]/[CSF HSV-1 Ab]) was 0.98 and HSV-1 Ab index(= [CSF HSV-1 Ab]/[serum HSV-1 Ab] divided by [CSF albumin]/[serum albumin]) was 62.4. Initial fluid attenuated inversion recovery(FLAIR) (TR/TE/TI = 6,882/110/1,700 msec) axial magnetic resonance(MR) imaging showed hyperintensity in the subfrontal area, inferomedial portions of the temporal lobes, cingulate gyri, and insular cortices bilaterally. Meningoencephalitis caused by HSV-1 was diagnosed based on the values of HSV-1 Ab ratio of serum to CSF(less than 20), of HSV-1 Ab index(larger than 1.91), and the findings of MR imaging. Diffuse white matter lesions manifesting hyperintensity on FLAIR imaging in the bilateral frontal and temporal lobes close to the affected cortices developed approximately six weeks after the onset despite administration of antiviral agent and steroid. The lesion extensively involved the white matter of the bilateral frontal and temporal lobes finally. The initial value of myelin basic protein(MBP) in CSF was 0.9 ng/ml (normal value: less than 4 ng/ml). Subsequent measurement of MBP in CSF about two, six weeks, two, three, and six months after the onset showed a marked increase of 233.9 ng/ml followed by a gradual decrease of 25.4 ng/ml, 18.4 ng/ml, 7.4 ng/ml and 4.3 ng/ml, respectively. Therefore, demyelination of the lesion in the cerebral white matter was suggested by the chronological change in FLAIR imaging and MBP in CSF.     

Acute hemorrhagic leukoencephalitis mimicking herpes simplex encephalitis: case report

Acute hemorrhagic leukoencephalitis (AHLE) is a more severe form of acute disseminated encephalomyelitis (ADEM) characterized by a fulminant clinical course and the presence of hemorrhagic necrosis of the white matter. We report the case of a 57-year-old woman who developed delirium following a respiratory infection. Magnetic resonance imaging of the brain disclosed signal abnormalities in the frontal and temporal lobes, usually found in herpes simplex encephalitis (HSE). Gram stain, India ink and acid-fast bacilli staining were all negative in CSF as was a polymerase chain reaction (PCR) for herpes simplex virus. A diagnosis of AHLE was made and the patient was treated with i.v. methylprednisolone 1g/day for 5 days. Despite treatment, the patient developed several neurological sequelae compatible with the severity of her illness.     

A case of herpes simplex encephalitis with periodic lateralized epileptiform discharges

A case of a 50-year-old male with herpes simplex encephalitis was reported. An EEG examination revealed periodic lateralized epileptiform discharges (PLEDs) on the right hemisphere on April 17, 1990. Another EEG performed on April 26 showed PLEDs on the left hemisphere, dominantly on the temporal lobe. On and after May 2, PLEDs have not been detected. SPECT showed hyperperfusion in the right temporal and occipital lobe son April 26. T1 weighted MRI examined on April 18 showed low signal intensity and T2 and proton weighted imagings revealed high signal intensity in the greater part of the right temporal lobe and a similar abnormality in a part of the left temporal lobe. Although the origin of PLEDs is still controversial, these findings suggest that, at least in the case of herpes simplex encephalitis, PLEDs appear in the early progressive stage of the inflammatory lesion.     

A case of herpes simplex encephalitis with noticeable findings of SPECT]

A 51-year-old man was admitted to our hospital because of fever, general fatigue and disturbance of consciousness. Neurological findings included disturbed consciousness, stiff neck and positive Kernig's sign. He was diagnosed as having herpes simplex encephalitis with HSV-DNA in the cerebrospinal fluid. MRI showed a lesion with low signal intensity in T1-weighted image and high signal intensity in T2-weighted image in the right temporal lobe. The single photon emission CT (SPECT) study showed discordance of 99mTc ethyl cysteinate dimer-SPECT (ECD-SPECT) and N-isopropyl-p-[123I]-iodoamphetamine-SPECT (IMP-SPECT). Decreased signal of ECD in the lesion where IMP uptake was increased could be due to decreased esterase activity. This report suggests that ECD-SPECT could fail to detect cerebral blood flow in the lesion with severe metabolic damage.