as opposed to spontaneous intermittent pain, perhaps?

I'm not sure I understand your question.  I've had the dubious (and not-so-enviable) distinction to experiencing several spinal fusion-induced surgeries and the related/consequent neuropathic pain that accompanies spinal compression injury.  Spontaneous neuropathic pain (not induced by painful or non-painful stimuli) is a very real clinical problem.  Can you tell me more specifically what you are asking?

Of course touch-evoked neuropathic pain is NOT spontaneous neuropathic pain.

My question is:

What is the difference between a spontaneous ONGOING neuropathic pain and a spontaneous neuropathic pain ?

As Michael Ossipov suggests: Does ongoing means permanent as opposed to intermittent ?

That's always been my understanding (ongoing = permanent).

I think Dr. Portillo-Salido's comments above about 'ongoing' pain make sense and are well-defined.

Dear Enrique, I know that sponatenous seems to mean idiopathic to scientists. However, Salter and Woolf used it (Lancet, 1999).

As clinician, this concept is very valuable to explain to our patient that their new neuralgic crisis is indenpendant of their past-activities. Spontaneous means stimulus-independant pain (allodynia), activities of daily living-independant pain and rest-independant pain. When a new crisis happens, they are always so guilty.: "what did I do wrong?" To explain to them that neuropathic pain are "spontaneous" is very helpful. Thank you very much indeed to these references (I knew the reference of Bennett, but NOT the two others).

In clinical practice, we observed partial tactile hypoaesthesia associated with spontaneous pain. Consequently, one of the etiology of spontaneous neuropathic pain is A-bêta neurofibre lesions

To find this territory of slight or strong tactile hypoaesthesia the key concept is: the largest territory of cutaneous distibution of the branches with its most distal point, its most proximal point, its most medial point and its most lateral point. Therefore, in a given patient, the distribution of a cutaneous branch can be expected to fall within the boundaries outlined in our atlas (Spicher et al., 2013, 2nd ed.).

The neuropathic symptom of burning pain is exactly in a part of this largest territory: the aesthesiography (the tactile hypoaesthesia territory)

The throbbing pain discharge until the most distal point of the aesthesiography.

The results of our prospective and consecutive study of 3514 aesthesiographies are published in this Atlas (compared with 96 clinical anatomy atlas).

However, the question is still open: Why do some authors add the extra information of spontaneous ONGOING pain ? Only because the neuralgic crisis becomes step by step more frequent, longer and and the end permanent ?

To illustrate the aesthesiology (aesthesiography, cutaneous senses, etc):

Della Casa, R., Mathis, F., Desfoux, N. & Spicher, C.J. (2010). Aesthesiology: A useful knowledge to assess Neuropathic Pain Patients (NPP); About 2256 Axonal Lesions of Cutaneous Branches. e-News Somatosens Rehab, 7(3), 128-137.

http://www.unifr.ch/neuro/rouiller/somesthesie/enews2010/e-News%20%207(3)#page=11.pdf