Quickly there is a condition of devocalization, occur coma and sharp vascular insufficiency develops. "
I don't know if a sentence translation is correct but I am sure about the word.

stupor seems to be too strong

Many attempts have been made at classifying the various "depths" of coma - namely, the classical one which distinguishes between ** obnubilation, torpor, **light coma and coma carus. Most authors distinguish three or four stages or "depths" (Mansuy et al. 1955; Fischgold and Mathis 1959; Loeb 1958).

Thus (Table 2), depending on the responses to these different tests, it will be possible to place the patient in one of five categories, according to the disturbances of perception:

P1 includes all the patients with no loss of con sciousness, patients who are "neurophysiologically" normal.
P2 represents **"obnubilation"**: these patients are disorientated in time and in space, and are unable to obey a written command. They can, however, pass all the other tests.
P3 represents what was classically known as **"torpor"**: they cannot give the name of flowers, and their understanding of the spoken word is poor. An order must be repeated many times before it is obeyed, and even then very slowly. But the blink reflex remains normal.
P4 represents the last stage of cortical percept ion, where only the blinking response to a threat persists.
P5 represents the stage where all perception is lost, indicating an organic or functional disturb ance of the cortical neurones.

I think this is more fitting because "stupor" or "torpor" is not something I have encountered in anything that I have seen in a medical field, personally or professionally (while translating or interpreting in hospitals) in the US.

Could be different for England though.

Или confusion

В принципе, однозначного соответствия англ. и рус. терминов нет. Переводя в обратную сторону, я часто использую "оглушенность" для "obtundation" и "confusion".

Вот неплохой медицинский сайт, где при описании отравления метанолом используется термин "obtundation":

http://www.emedicine.com/neuro/topic217.htm

Methanol
...
Neurological manifestations
Initially, the symptoms from methanol intoxication are similar to those of ethanol intoxication.
Headache may present early.
Nonspecific drowsiness may progress rapidly to ***obtundation*** and coma.
Seizures may occur, generally as a complication of the metabolic derangement or as a result of damage to the brain parenchyma.

Определение из Энциклопедического словаря мед. терминов:
оглушение (син.: ¶оглушенность, синдром оглушения сознания) — форма помрачения сознания, характеризующаяся повышением порога всех внешних раздражителей, замедлением и затруднением течения психических процессов, скудностью представлений, неполнотой или отсутствием ориентировки в окружающем.

Пример перевода (Неврология, Москва, Практика, 1997):

2. Level of unconsciousness. Abnormalities of consciousness comprise a continuum, ranging from mild confusion to total unresponsiveness. It is useful in clinical practice to categorize patients with abnormal consciousness according to stages of progressive unresponsiveness. Given the confusion surrounding the meanings of terms describing levels of consciousness, it is good practice to describe in detail on the record the responses of the patient to various stimuli. Use of terms such as lethargy, somnolence, or ***obtundation*** should be substantiated by a brief descriptive paragraph in the history.

2. Степень нарушения сознания может варьировать от легкой спутанности до полной ареактивности. Четких переходов между этими состояниями нет. На практике степень нарушения сознания определяют по реакции больного на раздражители. Поскольку термины, обозначающие степени нарушения сознания (такие, например, как заторможенность, сомноленция или ¶оглушенность), часто понимаются по-разному, в истории болезни лучше не просто ограничиться одним из них, а подробно описать реакции больного.